Temperature probes type T/TW

Transcription

1 Temperature probes type T/TW Contents 1 General Preface Introduction General instructions Scope Operating range Continuous Warnings contained glass monitoring in the operating 2 Safety instructions instructions (OI) General Notes on safety deliveries notes Product-specific Transport and storage safety notes Safety Warranty instructions notes for accessing reactors Avoiding Notes on damages return deliveries to the glass 3 Storage Safety 43.1 Transport Proper use 53.2 Product Qualified description personnel 4 Glass-lined temperature probes 4.1 Probe types 4.2 Joint features and properties 4.3 General information 4.4 Avoiding damages to peripheral devices Contents 5 Temperature probe type T 5.1 Measuring principle 15.2 Construction General of the T probe Introduction Transmitter TTH300 Ex 5.4 Technical data of T probe Scope Installation of the T probe Continuous Connection of the glass T probe monitoring 25.7 Start-up Safety and instructions maintenance of the T probe General Calibration safety of the T notes probe 5.9 Explosion protection 2.2 Product-specific safety notes 6 Temperature probe type TW Safety Measuring instructions principle for accessing 6.2 Construction reactors of the TW probe Avoiding Transmitter damages TTH300 Exto the glass Technical Storagedata of TW probe 6.5 Installation of the TW probe 46.6 Connection Transport of the TW probe 56.7 Start-up Product and description maintenance of the TW probe 6.8 Calibrating the TW probe 6.9 Explosion protection Annex 1 PTB 03 ATEX 2132 X Annex 2 Declaration of conformity Annex 3 A 3.1 Potentially hazardous atmospheres A 3.2 Atmospheric conditions A 3.3 Equipotential bonding A 3.4 Lightning protection A 3.5 Quatro-Pipe Operating Instructions e

2 Temperature probes type T/TW Temperature probes type T/TW 1 Preface The present operating instructions are designed to familiarize users with the construction of the glass-lined temperature probes and their use. The operating instructions should be accessible to the operating and maintenance personnel in order to ensure that all necessary information is available for any assembly and maintenance work. By knowing these operating instructions (OI), you can avoid damage to the measuring equipment and ensure trouble-free operation. The information contained in these operating instructions corresponds to the state of the art at the time it is printed and is provided to the best of our knowledge. We reserve the right to include any improvements, amendments and new developments in the operating instructions without prior notice. The actual design of products may differ from the information provided in the catalog if warranted by technical modifications resulting from product improvements. The proposal submitted by Pfaudler for a concrete application will be binding in this case. The latest edition will always supersede all previous ones. The present operating instructions are made available to our customers and interested parties free of charge. Reprints and copies as well as transformation into electronic forms, in whole or in part, shall require our written approval. All rights reserved. 2 General instructions 2.1 Operating range Glass-lined temperature probes are used to measure the product temperature in reactors and storage vessels as well as in pipelines. For the resistance of the probes, please refer to our publication no Never operate this measuring device outside its permissible operating conditions. 2.2 Warnings contained in the operating instructions (OI) In the operating instructions, the danger symbol m is used to draw your attention to especially important safety instructions. Compliance with these instructions is mandatory, because adherence to the instructions can avoid severe damage to people and/or equipment. 2.3 Notes on deliveries The respective scope of delivery is specified on the shipping documents attached to the shipment and corresponds to the valid purchase agreement. Check that the items delivered are complete and intact. If possible, keep the packing material for re-use for possible return shipments. 2.4 Transport and storage The probes should only be transported and stored in their closed original packaging. Where it is no longer available, the probes must be protected against shock and impacts. In order to guarantee an as-new condition of the probes, maintain the following storage conditions: n dry and dust-free n steady temperature and ventilation The probes do not need any preservatives, they are resistant to normal environmental influences. 2.5 Warranty notes Any warranty claims shall not be extended or limited by the information contained in the present operating instructions. For the exact warranty conditions, please refer to the Terms of Sale of Pfaudler Werke GmbH as amended. 2.6 Notes on return deliveries Before sending used probes to Pfaudler Werke GmbH or third parties for repair or other purposes, all parts must be cleaned and decontaminated. To protect our staff and for insurance reasons, your return shipment must be accompanied by a clearance certificate (refer to publication 332) on which you confirm that the probe was properly cleaned and decontaminated. You may obtain a form sheet for this purpose from us on request. 3 Safety For detailed safety instructions and information concerning explosion protection, please refer to the end of the operating instructions. 3.1 Proper use Any use of the probe for purposes other than described in the present operating instructions will adversely affect the safety and functioning of the measuring device and is therefore not allowed. It is important to note the safety instructions applicable to the electrical systems and equipment and all explosion protection provisions, if any. m Do not practice any working methods which may endanger safety. 3.2 Qualified personnel The probe may only be installed, started up and serviced by authorized personnel with special skills in measuring technology and in strict compliance with the present Operating Instructions as well as the valid provisions. The failure to observe these instructions no matter whether intentionally or negligently releases Pfaudler Werke GmbH from all liability and warranty claims. 2 Pfaudler GmbH 2

3 Temperature probes type T/TW 4 Glass-lined temperature probes 4.1 Probe types Pfaudler offers two different types of probes for temperature measurement which operate according to different physical measuring principles. These probe types are: n Temperature probe type T With this probe, a thermocouple performs the sensing function. Thermocouples are based on the physical effect of a charge shift in an electrical conductor (wire) along a temperature gradient. The free electrons move from the hot end of the wire to the cold end of the wire. n Temperature probe type TW This probe is equipped with a resistance thermometer as the sensor. Resistance thermometers are based on the physical effect that the electrical resistance of conductors and semiconductors changes subject to the temperature. 4.2 Joint features and properties Both probe types have a sensor that is fused into the glass. Thus, the sensor is excellently protected against aggressive media, and its placed directly in the product. This arrangement offers users the following advantages: n The probes have very short response times. The response behavior of the measuring probes type T and TW is shown in Fig. 1 in comparison to probes with plugged-in sensors. t [%] E T/TW Ta [s] Fig. 1 Time response Measured in inside the reactor (100 l) with water at 120 rpm T/TW measuring probe type T/TW on thermometer well, D = 40 mm Ta thermocouple with tantalum sensor in thermometer well, D = 40 mm E Reference measurement with unprotected pallaplat element (cannot be used in glass-lined reactor) n The sensors of the probes have not been simply screwed-in, producing error-prone sealing surfaces in the product. n Due to the quick and precise temperature measurement, the production process can be controlled safely and economically. In many cases, the product quality is also improved. MT_05_00001 n The sensors are not subject to ageing because they are made of extremely pure and highly resistant noble metals and have been fused into the glass layer in a chemically inert process. Glass is absolutely diffusion-tight, therefore, reaction with hydrogen is also excluded. 3 Pfaudler GmbH 3

4 Temperature probes type T/TW Temperature probes type T/TW 4.3 General information During a spark test, inflammable sparks may occur at the pores in the form of an electric arc. Therefore, spark testing may only be carried out outside of potentially explosive atmospheres. 4.4 Avoiding damages to peripheral devices When performing a spark test, please note the following information; otherwise, the components and/or the electronic transmitter may get damaged. n The measuring transducers for temperature, glass monitoring, capacitive sensors and other electronic/electric components that have been attached to the valve or the baffle must be disconnected prior to the spark test. n Suitable equipment must be employed for the test (impulse voltage). We recommend using the GlaSparker, our high-voltage tester n For glass lined measuring probes, the max. test voltage must not exceed 7 kv. n The contact window around the measuring probe site (e. g. P) must not be tested. In general, however, we recommend calling our technical service for performing the test. 5 Temperature probe type T 5.1 Measuring principle The temperature probe Type T will also be referred to as the T probe in the present Operating Instructions. As already mentioned, a thermocouple serves as the sensor of the T probe. A thermocouple consists of two electrical conductors made of different materials (wires) that are connected (in contact) to each other at one end. The contact point is the measuring location of the thermocouple. The two free wire ends constitute the reference location of the thermocouple. If the thermocouple is heated in the measuring location, a thermal voltage is present in the reference location. This thermal voltage depends on the temperature difference between the mea suring location and the reference location (temperature gradient along the thermocouple), and on the material combination of the two metal wires. For temperature measurements, the temperature of the reference location must be kept constant at 0 C, or it must be precisely measured in order to perform an appropriate adjustment in mv. To evaluate the thermal voltage, the free wire ends of the thermocouple (the reference location) are connected to a suitable transmitter. Standard EN defines the various material combinations for the production of thermocouples. These standardized material combinations are referred to as thermocouple types and marked by different capital letters. One of them is the letter T. m The T probe is not identical to thermocouple type T. The standardized thermocouple types are not suitable for the T probe for reasons of glassing technology. The positive branch of the T probe is made of a platinum-rhodium alloy (PtRh), the negative branch is made of a gold-palladium-platinum alloy (AuPdPt). This material combination is known as pallaplat. Table 1 shows the values of the basic characteristic of pallaplat. However, these values may only serve as reference values. The exact characteristic depends on the manufacturing batch of the pallaplat. For programming the transmitter (refer to Section 5.3), the characteristic that was determined for the specific pallaplat batch after production will be used. The values entered during programming will be indicated in the test report that is attached to each probe supplied. Only the Pfaudler-approved pallaplat compensating line (part no ) may be used as an extension for the thermocouple. 4 Pfaudler GmbH 4

5 Temperature probes type T/TW 5.2 Construction of the T probe Probe carrier The T probe can be installed in various probe carriers: n Baffles, thermometer well, Quatro- Pipe and C baffle (the term tubular probe will be used below for this type of probe carriers) n Ring probe n Valve shaft of outlet valves Tubular probe The thermocouple of tubular probes consists of very thin, narrow bands made of the pallaplat material combination. The pallaplat bands are fused into the glass layer. The measuring location, where the two pallaplat bands are in contact is normally at the end of the tube in order to measure the product temperature even at low liquid levels inside the reactor. When using tubular probes, several measuring locations may be fitted at the same or at different levels. The maximum possible number of measuring locations depends on the size of the tubular probe. For more details, please contact the Pfaudler Instrumentation department. In order to provide electrical connection to the thermocouple, the pallaplat bands fused into the glass are routed close to the terminal box and connected to the compensating line. In turn, the compensating line is introduced into the terminal box where it is connected to the transmitter. Tubular probes equipped with T probes can optionally be combined with the following measuring probes made by Pfaudler: n Typ P Measuring probe for glass monitoring n Typ FT Measuring probe for capacitive detection of filling limits or interfaces between liquids n Typ FS Measuring probe continuous, capacitive detection of filling levels n Typ TW Measuring probe for temperature measurement using a resistance thermometer For more details about possible combinations, please contact the Pfaudler Instrumentation department Ring probe The thermocouple of ring probes consists of very thin, narrow bands made of the pallaplat material combination. The pallaplat bands are fused into the glass layer. The measuring location is in the middle of the cylindrical inside area. Ring probes can be produced with a maximum of 4 measuring locations. In order to provide electrical connection to the thermocouples, the pallaplat bands fused into the glass are routed close to the terminal box and connected to the compensating line. In turn, the compensating line is introduced into the terminal box where it is connected to the transmitter. Ring probes equipped with T probes can optionally be combined with the following measuring probes made by Pfaudler: n Typ P Measuring probe for glass monitoring n Typ FT Measuring probe for capacitive detection of filling limits or interfaces between liquids For more details about possible combinations, please contact the Pfaudler Instrumentation department Valve shaft The measuring location of a probe mounted on a valve shaft is in the middle of the valve shaft on the product side. Power supply to the thermocouple is by means of pallaplat wires that are insulated and routed through the inside bore of the valve shaft. The wire ends are connected to the compensating line which in turn is introduced into the terminal box where it is connected to the transmitter type TTH300 (or terminals). With nominal sizes DN 80/50 or more, the T probe can be installed in a valve shaft. A maximum of 2 T measuring locations are possible. Optionally, a T probe can be combined with the a measuring probe Type P (for glass monitoring). For more details about this possible combination, please contact the Pfaudler Instrumentation department. 5 Pfaudler GmbH 5

6 Temperature probes type T/TW Temperature probes type T/TW 5.3 Transmitter A transmitter of the type TTH300 made by ABB is used as a standard for evaluating the signal measured by the T probe (the thermal voltage). The transmitter is a freely programmable unit that converts the measured signals of thermocouples and of resistance thermo meters into a standard potential-free 4-20 ma signal. The transmitter is integrated into the terminal box on the probe carrier already in the factory where it is also connected to the sensor lines. Based on product-dependent tolerances in the manufacture of pallaplat, the values of the characteristic may slightly deviate between batches. Therefore, the batch-specific characteristic is measured after the production of each batch. During the internal acceptance test in the factory, the TTH300 is parameterized with this batch-specific characteristic. The characteristic has a total of 32 intermediate points. The values of the characteristic are indicated in the test report that is attached to each probe supplied. The transmitter is programmed using the Smart Vision firmware. The TTH300 is also equipped with a HART interface which allows for programming of the transmitter on location. For more details concerning the transmitter, please refer to the documentation that is attached to each probe supplied. As a rule, it is possible to use other types or makes instead of the TTH300. However, the following conditions must be observed in this case: n The transmitter must be freely programmable and must be programmed with the batch-specific pallaplat characteristic. Third-party transmitters cannot be programmed by Pfaudler because we do not have the hardware and software necessary for that purpose. However, Pfaudler will support you with the programming of thirdparty transmitters. n The transmitter must have a reference location. n Pfaudler cannot provide any binding information concerning the accuracy of the measuring system as a whole if third-party transmitters are used. If the ambient temperature in the surroundings of the transmitter is excessively high on location (refer to Sect. 5.4), the transmitter must be installed next to the probe carrier in an area in which the temperature is lower. A pallaplat compensation line must be used to connect the terminal box on the probe carrier to the transmitter. Suitable compensating lines are available from Pfaudler (part no ). m The T probe must in all cases be operated in conjunction with a freely programmable transmitter, otherwise, the temperature measurement will not be correct. 6 Pfaudler GmbH 6

7 Temperature probes type T/TW 5.4 Technical data of T probe Sensor material: Resistance of pallaplat: Resistance of the compensating line: Pallaplat pos. branch made of platinum-rhodium neg. branch made of gold-palladium-platinum 30 Ω/m 0,33 Ω/m min/max temperature in the terminal box: 40/+80 C min/max operating temperature: 25/+200 C Measuring variance: max. ± 1,5 C Electrical data if used in potentially explosive atmospheres: Type of protection required for category 2 equipment Power and signal circuits Type of protection required for category 1/2 equipment Power and signal circuits EC type examination: Ex ia IIC For connection to certified, intrinsically safe electrical circuit only. L i negligible C i negligible Ex ia IIB For connection to certified, intrinsically safe electrical circuit only. The following maximum values apply to the measuring circuits of probes on a common probe carrier: U i = 30 V I i = 100 ma L i (probe) negligible C i (probe) negligible The maximum allowable inductance of all inductors in the supply circuits is 11 mh. The maximum allowable capacitance of all capacitors in the supply circuits is 180 nf. PTB 03 ATEX 2132 X 7 Pfaudler GmbH 7

8 Temperature probes type T/TW Temperature probes type T/TW 5.5 Installation of the probe carriers Installation of tubular probe The term tubular probe is used for the following probe carriers in this context: n Baffles n Thermometer well n Quatro-Pipe n C baffles Before installing a tubular probe in a reactor or a pipeline, you should verify whether there is sufficient distance to the agitator and the reactor wall. If necessary, suitable spacers or reducing flanges must be used. Assembly process: t Place flange gasket on nozzle. t Protect the nozzle and the probe against damage by inserting a piece of cloth or a PTFE sleeve into the nozzle. Slowly introduce the tubular probe into the reactor through the nozzle. Avoid pendulum motion. t Tighten flange screws evenly crosswise with the prescribed tightening torque; (cf. Tab. 3). m When using your own reducing flanges, please make sure that the element covering the contact area below the terminal box does not sit on the reducing flange (cf. Fig. 2). In the event of non-compliance, the glass may be damaged at the bottom side of the flange, and the fused-in metal strips may be interrupted Installation of ring probe The ring probe may generally be installed in any position inside the pipeline. However, it must be noted that the T probe does not work unless the measuring location is sufficiently covered with product. In radial direction, the measuring location is in the same place as the terminal box. The ring probe is be installed in the pipeline between 2 flanges using gaskets. Tighten flange screws evenly crosswise with the prescribed tightening torque; (cf. Tab. 3) Installation of outlet valve For details concerning the installation, please refer to our Operating Instructions 322. These Operating Instructions are attached to each valve supplied. They are available from Pfaudler on request. collision area MT0010_1E Fig. 2 Installation example with reducing flange Table 3 Tightening torques of glass-lined flange connections Flange Screws Max. tightening torques in Nm with admissible operating pressures of: 1 to +10 bar 1 to +16 bar DN50 4 x M DN80 8 x M DN100 8 x M DN150 8 x M DN200 8 x M Pfaudler GmbH 8

9 Temperature probes type T/TW + red violett 3 1 T probe power supply unit with electrical isolation Ex ia/ib max. 30 V DC 100 ma }optional floating change-over contacts 6 +5 current output 4-20 ma power Supply 24 V DC/AC (230 V AC) MT_05_003_1e Fig. 3 Connection diagram of the T probe 5.6 Connection of the T probe The following information only applies to T probes in connection with the TH02-Ex transmitter. A power supply unit with the following specifications is necessary for power supply: n Supply current: I S = 0-20 ma n Supply voltage: U S = 8, V DC n in potentially explosive atmospheres: U i = 8, ,4 V DC For applications in potentially explosive atmospheres, power supply units in intrinsically safe design must be used. The power supply unit must be installed outside the potentially explosive area. The installation instructions of the manufacturer are mandatory in this respect. The connection between the power supply unit and the transmitter can be made using standard signal cables. The probe carriers must be grounded using copper or stainless steel wires with a minimum conductor area of 10 mm 2. The electrical connection is made in compliance with the connection diagram shown in Fig. 3. Connection is identical for all probe carriers. 5.7 Start-up and maintenance of the T probe No start-up procedure is necessary for T probes supplied together with the standard transmitter. When the transmitter has been connected to the power supply unit, the T probe is ready for use. However, we recommend verifying whether the transmitter s measuring range as set by Pfaudler complies with your requirements. The measuring range setting is indicated on a rating plate each on the transmitter and in the terminal box as well as in the test report. If necessary, the measuring range can be changed. Upon final acceptance in the factory, a functional test and a single-point calibration will be performed. A test report will be prepared which is attached to each probe. If the T probe is ordered and delivered without a transmitter, it is the operator s responsibility to ensure that a suitable transmitter is used and configured (refer to Sect. 5.3). The values comprised in the characteristic of the thermocouple are provided in the attached test report. Due to its special construction (thermocouple fused into glass layer) and noncritical operating conditions, the probes are not subject to ageing. Therefore, inspections (calibration) of the thermocouple are not necessary for measuring reasons. As a result, the T probe is maintenance-free. 9 Pfaudler GmbH 9

10 Temperature probes type T/TW Temperature probes type T/TW If it is used for processes, however, which are associated with the risk of product deposits, it must be verified whether or not product has accumulated on the probe carrier. Deposits must be removed using suitable means and methods. 5.8 Calibration of the T probe General instructions As mentioned before, the thermocouple has been fused into the glass layer, thus forming an integral part of the probe carrier. Calibrating the thermocouple separately is not possible for this reason. It is most practical to calibrate the T probe with the probe carrier installed because stable, reproducible temperature conditions at the T probe are most conveniently achieved. Calibration outside the reactor or pipeline is very problematic because there is considerable heat dissipation, which results in instable temperature conditions at the thermocouple, due to the shape and size of the probe carriers. For calibration, the reactor or the pipeline must be filled either with product or with water. A steady temperature at the transmitter must be ensured during calibration. For this reason, the terminal box should be closed. For calibrating tubular probes, the reactor must be filled until the immersion depth of the measuring location is at least five times the tube diameter. When calibrating inside a reactor, the agitator must turn slowly in order to ensure an even temperature distribution inside the liquid. For ring probes, the pipeline must be fully filled. Ring probes may also be calibrated outside the pipeline due to their compact dimensions. For this purpose, the probe must then be immersed into a suitable vessel. Caution! Do not immerse the terminal box. When calibrating outlet valves, the valve cone must be sufficiently covered with product so as to ensure a stable temperature condition in the measuring location. Furthermore, the agitator must be slowly turned during calibration Calibrating the measuring chain In order to calibrate the entire measuring chain including the sensor, transmitter and display unit, immerse a calibrated reference thermometer into the liquid and compare its measured value (reference value) with the value measured by the T probe (actual value). If it is necessary to calibrate the T probe at different temperatures, we recommend calibrating it in icy water at 0 C and in boiling water at 100 C. The result will be reliable information concerning the accuracy of the entire measuring chain and the actual temperature conditions in the subsequent production process. If an excessive, inadmissible measuring deviation is detected during calibration, the individual elements of the measuring chain must be verified or calibrated Calibrating the sensor Actually, it is not necessary to calibrate the sensor (thermocouple) for technical reasons because the sensor is not subject to ageing (refer to Sect. 5.7). However, in some cases the sensor has to be calibrated to comply with internal or process-related requirements. The Pfaudler T-Calibrator (part no ) and the Smart Vision firmware must be available in order to calibrate the thermocouple. For more information and a detailed description of the calibration process, please refer to the Operating Instructions of the T-Calibrator Calibrating the transmitter In order to calibrate the transmitter, a process calibrator is connected to the transmitter input that serves to simulate the thermocouple s characteristic. Then, the voltage values of the characteristic are entered one by one at the process calibrator. In parallel, the actual values of the transmitter (input and output signal) are compared to the programmed values (values of the characteristic). The values of the characteristic are indicated in the test report that is attached to each probe supplied. It is important to deactivate the internal reference point of the transmitter during calibration. Please refer to the Operating Instructions of the TH02-Ex unit for a description of how to deactivate the reference point Calibrating the display unit In order to calibrate the display unit, an additional, calibrated display unit is looped into the transmitter s output circuit, and the two values displayed as actual and programmed values must be compared. 5.9 Explosion protection The tubular and ring probes with an integrated T probe have been approved for use in potentially hazardous atmospheres of zone 0 in accordance with the EC type examination certificate No. PTB 03 ATEX 2132 X. For outlet valves with an integrated T probe, an EC type examination certificate has been applied for. 10 Pfaudler GmbH 10

11 Temperature probes type T/TW 6 Temperature probe type TW 6.1 Measuring principle The temperature probe Type TW will also be referred as the TW probe in the present Operating Instructions. As already mentioned, a resistance thermometer serves as the sensor of the TW probe. The measuring principle of resistance thermometers is based on the fact that the electrical resistance of all conductors and semiconductors changes with the temperature. The amount of change in referred to as varies depending on the material used. The relative change of the electrical resistance as a function of the temperature, R/ t, is referred to as the temperature coefficient. This value is not constant over the whole temperature range. Rather, it is a function of the temperature. The relationship between resistance and temperature is subject to higher-order mathematical polynomials for calculating the characteristic of a resistance thermometer. The special properties of platinum, such as high measuring accuracy, high temperature resistance, chemical resistance, an approximately linear characteristic as well as an excellent reproducibility of the thermo-electrical properties, were reason enough to produce most resistance thermometers from this metal today. Since platinum can also be easily glassed, it is also used for the TW probe. The resistance values of resistance thermometers made of platinum have been standardized and are referred to as Pt 100, Pt 500 and PT The number specifies the nominal resistance in Ohm at a temperature of 0 C. Therefore, a Pt 100 has a nominal resistance of R 0 = 100 Ω. For these standardized measuring resistances, basic value series (characteristics) have been specified in EN The measured signal is evaluated by the transmitter based on this characteristic in order to determine the temperature. For the TW probe, no Pt 100 to the EN standard was used as resistance thermometer. For technical reasons, the TW probe cannot be produced with an exact resistance value of 100 Ω. The resistance of the TW probe is 100 ± 3 Ω. Therefore, it is absolutely necessary to use a programmable transmitter (refer to Sect. 6.3) that compensates the deviation from the 100 Ω characteristic in order to evaluate the measured signal. 6.2 Construction of the TW probe The TW probe can be installed in the following probe carriers: n Paddle-type baffles n Thermometer well n Quatro-Pipe It is not possible to install the TW probe in a ring probe, a C baffle or a valve shaft. The resistance thermometer consists of a very thin platinum band that is spirally wound around the end of the probe carrier tube. The platinum band is fused into the glass layer. The maximum possible number of measuring locations on a tubular probe depends on the size of the probe carrier. For more details, please contact the Pfaudler Instrumentation department. The measuring locations are always at the same level. Measuring locations at different levels can only be provided using the T probe (refer to Sect. 5) The supply wires of the resistance thermometers are also made of platinum. The supply wires fused into the glass are routed close to the terminal box where they are connected to terminal wires. In turn, the terminal wires are introduced into the terminal box where they are connected to the transmitter type TH02-Ex (or terminals). 11 Pfaudler GmbH 11

12 Temperature probes type T/TW Temperature probes type T/TW The TW probe is designed in four-wire technology (2 parallel supply bands each). Therefore, TW probes can be connected in a four-wire circuit. With this measuring method, a constant measuring current flows through 2 wires, whereas the temperature-dependent voltage drop at the measuring resistor is measured via the remaining 2 wires. In a fourwire circuit, the influence of the supply conductor resistance on the measured result is totally neutralized. Probe carriers equipped with TW probes can optionally be combined with the following measuring probes made by Pfaudler: n Typ P Measuring probe for glass monitoring n Typ FT Measuring probe for capacitive detection of filling limits or interfaces between liquids n Typ FS n Typ T Measuring probe continuous, capacitive detection of filling levels Measuring probe for temperature measurement using a thermocouple For more details about possible combinations, please contact the Pfaudler Instrumentation department. 6.3 Transmitter TTH300 A transmitter of the type TTH300 made by ABB is used as a standard for evaluating the signal measured by the TW probe. The transmitter is a freely programmable unit that converts the measured signals of resistance thermometers and thermocouples into a standard potential-free 4-20 ma signal. The transmitter is integrated into the terminal box already in the factory where it is also connected to the sensor lines. As already mentioned in Sect. 6.1, the resistance thermometer for the TW probe cannot be produced to have a resistance of exactly 100 Ω at 0 C. For this reason, the exact resistance in Ω of the resistance thermometer is measured upon completion of the TW probe. During the internal acceptance test in the factory, the transmitter is parameterized with the characteristic of this Ω value. The characteristic has a total of 32 intermediate points. The values of the characteristic are indicated in the test report that is attached to each probe supplied. The transmitter is programmed using the Smart Vision firmware. The TTH300 is also equipped with a HART interface which allows for programming of the transmitter on location. For more details concerning the transmitter, please refer to the documentation that is attached to each probe supplied. As a rule, it is possible to use other types or makes instead of the TTH300. However, the following conditions must be observed in this case: n The transmitter must be freely programmable and must be programmed with the probe-specific characteristic. Third-party transmitters cannot be programmed by Pfaudler because we do not have the hardware and software necessary for that purpose. However, Pfaudler will support you with the programming of third-party transmitters. n Pfaudler cannot provide any binding information concerning the accuracy of the measuring system as a whole in this case. If the ambient temperature in the surroundings of the terminal box is excessively high on location (refer to Sect. 6.4), the transmitter must be installed next to the probe carrier in an area in which the ambient temperature is lower. The 4-wire signal lead may be used to connect the terminal box on the probe carrier to the transmitter. m The TW probe must in all cases be operated in conjunction with a programmable transmitter, otherwise, the temperature measurement will not be correct. Table 3 Tightening torques of glass-lined flange connections Reactor type AE AE/BE/CE E BE/CE Nominal reactor size 63 to to to to baffle with stuffing box baffle/thermowell with flange 8000 to Quatro Pipe Pfaudler GmbH 12

13 Temperature probes type T/TW 6.4 Technical data of TW probe Sensor material: Platin Resistance of the sensor material: ca. 40 Ω/m Resistance of the feed conductors: ca. 10 Ω/m min/max temperature in the terminal box: 40/+80 C min/max operating temperature: 25/+200 C Measuring variance: max. ± 1 C Electrical data if used in potentially explosive atmospheres:: Type of protection required for category 2 equipment Power and signal circuits Type of protection required for category 1/2 equipment Power and signal circuits EC type examination: Ex ia IIC For connection to certified, intrinsically safe electrical circuit only. L i negligible C i negligible Ex ia IIB For connection to certified, intrinsically safe electrical circuit only. The following maximum values apply to the measuring circuits of probes on a common probe carrier: U i = 30 V I i = 100 ma L i (probe) negligible C i (probe) negligible The maximum allowable inductance of all inductors in the supply circuits is 11 mh. The maximum allowable capacitance of all capacitors in the supply circuits is 180 nf. PTB 03 ATEX 2132 X 13 Pfaudler GmbH 13

14 Temperature probes type T/TW Temperature probes type T/TW Pt 100 white red green black TW-Sonde power supply unit with electrical isolation Ex ia/ib max. 30 V DC 100 ma - }optional floating change-over contacts 6 +5 current output 4-20 ma power supply 24 V DC/AC (230 V AC) MT_05_0004_1e Fig. 4 Connection diagram of the TW probe 6.5 Installation of the TW probe As already mentioned, the TW probe can be installed in the following probe carriers: Paddle-type baffles, thermometer wells, Quatro Pipe These probe carriers are generally also referred to as tubular probes. Before installing a tubular probe in a reactor or a pipeline, you should verify whether there is sufficient distance to the agitator and the reactor or pipeline wall. If necessary, suitable spacers or reducing flanges must be used. Assembly process: t Place flange gasket on nozzle. t Protect the nozzle and the probe against damage by inserting a piece of cloth or a PTFE sleeve into the nozzle. Slowly introduce the tubular probe into the reactor through the nozzle. Avoid pendulum motion. t Tighten flange screws evenly crosswise with the prescribed tightening torque; (cf. Tab. 3). m When using your own reducing flanges, please make sure that the element covering the contact area below the terminal box does not sit on the reducing flange (cf. Fig. 2). In the event of non-compliance, the glass may be damaged at the bottom side of the flange, and the fused-in metal strips may be interrupted. 6.6 Connection of the TW probe The following information only applies to TW probes in connection with the transmitter. A supply unit with the following specifications is necessary for power supply: n Supply current: I S = 0-20 ma n Supply voltage: U S = 8, V DC n in potentially explosive atmospheres: U i = 8, ,4 V DC For applications in potentially explosive atmospheres, supply units in intrinsically safe design must be used. The power supply unit must be installed outside the potentially explosive area. The installation instructions of the manufacturer are mandatory in this respect. The connection between the power supply unit and the transmitter can be made using standard signal cables. The probe carriers must be grounded using copper or stainless steel wires with a minimum conductor area of 10 mm 2. The electrical connection is made in compliance with the connection diagram shown in Fig Pfaudler GmbH 14

15 Temperature probes type T/TW 6.7 Start-up and maintenance of the TW probe No start-up procedure is necessary for TW probes supplied together with the standard transmitter. When the electrical connection of the transmitter to the power supply unit has been made, the TW probe is ready for use. However, we recommend verifying whether the transmitter s measuring range as set by Pfaudler complies with your requirements. The measuring range setting is indicated on a rating place each on the transmitter and in the terminal box as well as in the test report. If necessary, the measuring range can be changed. Upon final acceptance in the factory, a functional test and a single-point calibration will be performed. A test report will be prepared which is attached to each probe. If the TW probe is ordered and delivered without a transmitter, it is the operator s responsibility to ensure that a suitable transmitter is used and configured (refer to Sect. 5.3). The values comprised in the characteristic of the resistance thermometer are provided in the attached test report. Due to its special construction (resistance thermometer fused into glass layer) and non-critical operating conditions, the probes are not subject to ageing. Therefore, inspections (calibration) of the resistance are not necessary for measuring reasons. As a result, the TW probe is maintenance-free. If it is used for processes, however, which are associated with the risk of product deposits, it must be verified whether or not product has accumulated on the probe carrier. Deposits must be removed using suitable means and methods. 6.8 Calibrating the TW probe General instructions As mentioned before, the resistance thermometer has been fused into the glass layer, thus forming an integral part of the probe carrier. Calibrating the resistance thermometer separately is not possible for this reason. It is most practical to calibrate the TW probe with the probe carrier installed because stable, reproducible temperature conditions at the T probe are most conveniently achieved. Calibration outside the reactor or pipeline is very problematic because there is considerable heat dissipation, which results in instable temperature conditions at the resistance thermometer, due to the shape and size of the probe carriers. For calibration, the reactor or the pipeline must be filled either with product or with water. A steady temperature at the transmitter must be ensured during calibration. For this reason, the terminal box should be closed. For calibrating tubular probes, the reactor must be filled until the immersion depth of the measuring location is at least five times the tube diameter. When calibrating inside a reactor, the agitator must turn slowly in order to ensure an even temperature distribution inside the liquid Calibrating the measuring chain In order to calibrate the entire measuring chain including the sensor, transmitter and display unit, immerse a calibrated reference thermometer into the liquid and compare its measured value (reference value) with the value measured by the TW probe (actual value). If it is necessary to calibrate the TW probe at different temperatures, we recommend calibrating it in icy water at 0 C and in boiling water at 100 C. The result will be reliable information concerning the accuracy of the entire measuring chain and the actual temperature conditions in the subsequent production process. If an excessive, inadmissible measuring deviation is detected during calibration, the individual elements of the measuring chain must be verified or calibrated Calibrating the sensor Actually, it is not necessary to calibrate the sensor (resistance thermometer) for technical reasons because the sensor is not subject to ageing (refer to Sect. 5.7). However, in some cases the sensor has to be calibrated to comply with internal or process-related requirements. For calibrating the probe, a process calibrator capable of measuring the resistance of the resistance thermometer and the product temperature in a four-wire circuit must be used. The measured values (actual values) must then be compared to the programmed values (values taken from the characteristic) Calibrating the transmitter To calibrate the transmitter, an adjustable precision resistor must be connected to the transmitter input. Then, the resistance values from the characteristic are input one by one, and the related temperature (programmed value) is compared to the output value of the transmitter (actual value). The values of the characteristic are indicated in the test report that is attached to each probe supplied Calibrating the display unit In order to calibrate the display unit, an additional, calibrated display unit is looped into the transmitter s output circuit, and the two values displayed as actual and programmed values must be compared. 6.9 Explosion protection The tubular with an integrated TW probe have been approved for use in potentially hazardous atmospheres of zone 0 in accordance with the EC type examination certificate No. PTB 03 ATEX 2132 X. 15 Pfaudler GmbH 15

16 Annex 1 PTB 03 ATEX 2132 X Annex 1 PTB 03 ATEX 2132 X 16 Pfaudler GmbH 16

17 Annex 1 PTB 03 ATEX 2132 X 17 Pfaudler GmbH 17

18 Annex 1 PTB 03 ATEX 2132 X Annex 1 PTB 03 ATEX 2132 X 18 Pfaudler GmbH 18

19 Annex 1 PTB 03 ATEX 2132 X 19 Pfaudler GmbH 19

20 Annex 1 PTB 03 ATEX 2132 X Annex 1 PTB 03 ATEX 2132 X 20 Pfaudler GmbH 20

21 Annex 1 PTB 03 ATEX 2132 X 21 Pfaudler GmbH 21

22 Annex 1 PTB 03 ATEX 2132 X Annex 1 PTB 03 ATEX 2132 X 22 Pfaudler GmbH 22

23 Annex 2 Declaration of conformity 23 Pfaudler GmbH 23

24 Annex 3 Annex 3 A 3.1 Potentially hazardous atmospheres The application of the T or TW measuring probe in potentially hazardous atmospheres belonging to zone 0 is permitted if the following conditions are maintained: n Connection to certified, intrinsically safe electrical circuit only with proper type of protection n Intrinsically safe Ex ia IIC with the following maximum values: U i = 30 V I i = 100 ma P i = 750 mw L i negligible negligible C i The maximum allowable inductance of all inductors = L 0 in the supply circuits is 11 mh. The maximum allowable capacitance of all capacitors = C 0 in the supply circuits is 180 nf. A 3.2 Atmospheric conditions The process pressure of the media or the media temperature must be in between 0,8 bis 1 bar or C for all applications that require category 1/2 equipment. If these conditions of use are not complied with at the measuring sensor, it must be ensured that the measuring sensor does not heat up itself (not even in the event of fault). Please note that the safe operation of the plant with respect to pressures/temperatures of the substances used are the responsibility of the operator. The characteristic data supplied by the manufacturer shall be observed. A 3.3 Equipotential bonding Since the intrinsically safe circuit of the measuring electrode is grounded during operation, a joint equipotential bonding system must exist in the course of the entire wiring of the intrinsically safe circuit and the reactor or pipeline must be included in this equipotential bonding system. A 3.4 Lightning protection If the T or TW probe is installed in systems that must be protected against ignition hazards caused by strikes of lightning, the probe must be included in lightning protection. The lightning protection system must comply with the requirements of VDE A 3.5 Quatro-Pipe Like the reactor wall, the Quatro Pipe constitutes a separator between the areas of zone 1 and zone 0. Therefore, the Quatro Pipe may only be used in conjunction with the integrated T or TW probe if the internal tube is closed by the related glass-lined blind flange. If it should be necessary to open the internal tube, e.g., for sampling purposes, the operator must take proper measures to ensure that no explosive atmosphere is released and/or flames can enter the reactor from outside. 24 Pfaudler GmbH 24

25 Notes 25 Pfaudler GmbH 25

26 Notes Notes 26 Pfaudler GmbH 26

27 Notes 27 Pfaudler GmbH 27

28 The information provided in this documentation corresponds to the state of the art at the time of printing. It is published in good faith. However, we will accept no warranty claims based on the information provided in this documentation. We reserve the right to include improvements, amendments and new findings in this documentation without prior notice. The actual design of products may deviate from the information contained in the calatoge if technical alterations and product improvements so require. The proposal made by Pfaudler for a concrete application will be binding in such cases. The present documentation is made available free of charge to our customers and other interested parties. The right to print or copy this documentation, or any parts there of, or to convert the same into electronic form shall be subject to our written permission. All rights reserved by us. Pfaudler GmbH P.O. Box 1780 D Schwetzingen Pfaudlerstraße D Schwetzingen Phone Telefax info@pfaudler-instrumentation.com