Electromagnetic Flowmeter Comet F

Transcription

1 Electromagnetic Flowmeter Comet F - Exact measurements - Comfortable calibration with PC - No setup elements - No pressure loss - Periodic cleaning of electrodes - Data backup during power failure - Communication with PC - Robust and versatile design - Reasonable price Doc. no.: 155, en_cat_cometf, 5/2015

2 Principle of operation Meter is based on the principle of electromagnetic inductive. It is designed to measure the flow of electrically conductive liquids. It is particularly suitable where traditional mechanical meters are not sufficiently reliable and accurate due to the principle of measurement. The only limiting factor of the electromagnetic flowmeter is the requirement to keep a minimum electrical conductivity of the liquid and a small content of ferromagnetic particles. Description of the meter Design of the meter allows measuring fluid chemically highly aggressive, abrasive, with high solids content and a pasty consistency. Pressure loss caused by the meter is practically zero. Meter achieves high accuracy and a large range of maximum and minimum measured flow. Meter consists of sensor built into the pipeline and electronics housing connected by cable. The electronics housing contains an electronic converter controlled by a microprocessor and equipped with display. Values on the display: - Amount of liquid passed through and the operating time - Instantaneous flow - Status and error report Keeping measured data in case of power failure ensures processor backup power supply and memory EEPROM. EEPROM allows digital calibration and adjustment of the measuring range without the use of analog adjusters. Complete absence of analog adjustment elements is ensured by high long term stability and accuracy. Protection of sensor and electronics housing in sealed aluminum housing. Robustness cabinet provides very good protection against environmental influences. Advantages resistance against environmental influences is especially true when deployed in industrial environments. Available outputs for remote transmission: - Analog - Pulse - Digital serial data output Possibility of automatic electrode cleaning protection against dirt and incrustations (supplied on request). Comfortable calibration Sensor Converter with PC. Display Block diagram of the electromagnetic flowmeter Comet F Excitation impulse output fast impulse output slow analog output data output Source 2 of 10

3 Example of applications SECTORS Food Water Paper Mining Chemistry Metallurgy Special applications EXAMPLE OF APPLICATION beer, wine, milk, cream, vinegar, fruit juices, sugar and starch solutions, chocolate paste, slurry grated potatoes, beets and others. supply, waste water, sewage sludge slurry cellulose, extracts, dyes coal slurry, slurry coal, mine water most chemical solutions strongly aggressive cooling water, wastewater after consultation with the manufacturer Specifications Flowmeter supplied as required either as an operational instrument or measuring instrument. In both cases, the accuracy is the same, the difference is only in relation to metrological legislation. Specified meters Subject to state metrological supervision, periodic verification and they are calibrated as a whole in one measuring range, without the possibility of changing the scope in the operator place. For measuring instruments in the function of the water meter is defined accuracy: ± 2% in the range of Q max Q t, and ± 5% in the range of Q t Q min where Q t is a transition flow. Operating meters Operating meters are not subject of the state supervision. They are calibrated as a whole and the operator has the option to change the measuring ranges without additional calibration. It is assumed accuracy stated by the manufacturer. Produced diameters and basic range of measurements Note! On request the meter can be produced also in non standard range 3 of 10

4 Technical meter accuracy is given by the construction and the material used. The actual meter error is the sum of technical error and errors in calibration. Technical meter error is expressed by the formula: δ 0 = Q0.5% %Q max Q is the instantaneous flow rate and Q max is the maximum flow range Range of allowed errors of specified meters Actual flowmeter error Sensor Curve of meter errors Minimum conductivity of liquids 5μS/cm Length of the conenting cables standard 6 m, special max. 25 m Nominal pressure Protection according to ČSN IP 65 Electrodes Installation standard 1,6 Mpa special 2,5 Mpa Straight pipe length 5DN and 3DN behind the sensor flat flanges acc. to ČSN standard steel chem. resistance titanium, platinum Fluid temperature, chemical and antiabrasive resistance Lining Antiabrasion Chem. resistance Temperature Food PP bad good 80 C yes SILASTIC good good 150 C yes HALAR small great 120 C yes RUBBER good small 90 C no Dimensional series DN10 DN200 Dimensional series DN300 DN600 4 of 10

5 Main dimensions of manufactured sensors DN (mm) A (mm) B (mm) C (mm) Weight (kg) , , , , , , , , , , ,0 300 Ø ,0 400 Ø ,0 500 Ø ,0 600 Ø ,0 Note! Sensors covers diameters 300 mm and above have a cylindrical shape (Ø = A = B) Converter Power 220V (+10% 15%), 50Hz Input of the whole system 12VA max. Protection acc. ČSN IP65 Weight 4,2kg Operating temperature Storage temperature Output (galvanically separated) 1. Pulse rapid 2. Pulse slow 3. Analog 4. Serial data output Further outputs characteristics for remote transmissions 5 C to +45 C protect from direct sunlight 20 C to +80 C relative humidity max. 80% 30V/20mA max. opened collector 30V/20mA max. opened collector Ma or 4 20mA to load 500Ω max. 30V/20mA max. opened collector transmission speed 2400 bit/s 1. Impulse output rapid a) Sends pulses value of 0.1; 1; 10 or 100dm 3, depending on the maximum flow rate of a specific flowmeter type b) May indicate a maximum of 100 units per second. This number determines the size of the pulse for a particular flowmeter. 2. Pulse output slow a) Transmits pulses with a value of 1 m 3 5 of 10

6 Both pulse outputs indicate the flow of pulses summarized as the rising and descending with an interval of 640 ms. The leading and trailing edges of the pulse in the series have a time lag of 10 ms. 3. Analog output a) indicates instantaneous flow b) is used as the active current loop 0 or 4 to 20 ma. The value 20 ma can be assigned to any immediate flow. c) Analog output parameters are stored in EEPROM memory and can be adjusted using the computer at any time during operation. d) Unless stated otherwise, analog output is set at the factory to match the rated current 20mA flow rate of O max. 4. Serial data output a) The normal one way (output only) serial, optocoupler isolated. b) Possible to link it to the standard 20 ma current loop, which is on the side of the meter passively keying by output transistor optocoupler. c) Closed optocoupler corresponds to a logical level H. d) Transmission rate is 2400 bit/s. e) Dispatched 8 data bits, no parity, one START bit and one STOP bit. f) In each measuring cycle (640ms) is sent to the data output (terminals D +, D ) data block. Data block Contains 42 characters ASCII, followed by two termination characters CR LF. Has 5 items that follow each other. Each item has two initial characters. The first character is a slash (/) and the second character defines the item. Character format Format of the data block Closed transistor Opened transistor Marks Meaning of an item Position Quantity /Nxxxxxx Serial number /Vxxxxx.x Liquid volume (m3) /Txxxxx.x Total measurement time /Qxxx.xxx Instantaneous flow (dm3/s) /Sxxxxx Control sum CR LF Termination characters Explanation of the table format data block Decimal point position for displaying the liquid volume is set during calibration or optional by INIT program. Character "x" represents number 0 9th Zeros from left are replaced by spaces, except for the serial number, where they are left Control sum is the sum of the decimal equivalents of ASCII characters in positions If the device is not in measurement mode or if an error occurs, the data output sent a status report, which has 10 characters. The first two characters are always"/m" 6 of 10

7 Format of the status report Marks Meaning of message Position Quantity /M NOC Powerup CR LF /M Cxx Cleaning of electrodes CR LF /M Exx Error messages CR LF /M SEL Inserting constants CR LF Instructions for use 1. Installation Check the serial number of the sensor and electronics. During installation, it is necessary to comply with applicable electrical codes It s not allowed to connect or disconnect the jumper cables under tension. After the mechanical installation of sensors in the pipeline (flow direction must be consistent with the arrow on the sensor) and fixing the electronics housing the sensor cable has to be attached to the terminal block (see. mounting block diagram). Skeleton of the sensors must be electrically connected with the flowing fluid! Connecting pulse, current and output data can also be according to the mounting block diagram. After connecting all cables the unit will activate by the main supply. Device does not contains the power switch and it needs to be insured and turned off by on another device. Device operates in safety class l protective terminal connected to ground (body casing). 7 of 10

8 2. Turn on and operating Each time you turn on the device will automatically start testing of digital part and eventual cleaning of electrodes (in case that a customer will order that equipment). Measured values are displayed on the two line display. Identification of the values displayed is provided by alphanumeric characters. If the sensor is not full of liquid, the device evaluates this as a zero flow. Each power turn on starts the entrance electronics test: If the error was detected, the test is repeated continuously and measurements don t occur. When properly progress after the test step CL 47 (after about 30 seconds) the display shows cumulative values: The decimal point of the cumulative amount of liquid passed is as default by calibration or by program INIT. Pressing the button on the electronic box display the current flow mode: Press the button to see the cumulated values 8 of 10

9 Error messages Processor constantly scans the correct function of electronics and checks whether the flow rate or output pulses are within the allowable limits. Some of error messages are only intended for service purposes. Significant reports for users: Incorrect flow direction Pulse output is more than 100 units per second. Measured flow was for 5 minutes about 20% larger than Q max. Backup battery voltage has dropped below the observed value (for service purposes) Pipeline assembly principles Straight pipe length Min. 5DN before and 3DN behind the sensor reduction up to 8 are counted. Grounding Sensor flanges connect the pipe flanges grounding connectors (detail A). When using plastic pipes it has to be used on the flanged joints metal inserts to ensure contact of the liquid with the ground sensor. Necessary condition for operation Location of the sensor in piping must ensure complete filling of the sensor with water without aeration. Air in sensor exhibits an inaccurate measurement. Against aeration is recommended to place the sensor in a "trap". 9 of 10

10 Ordering When ordering please state: Sensor diameter Flow range Any requirements to the meter Demand for electrolytic cleaning electrodes Demand for program INIT Special request for cable lengths Special request for nominal fluid pressure Specifications of the measured liquid Max. product temperature of the measured liquid Warranty Electrical conductivity of the measured liquid (if it is a liquid with low electrical conductivity) Chemical aggression of the measured liquid Abrasiveness of the measured liquid Manufacturer provides a warranty of 12 months from purchase. Defects caused by improper handling are not manufacturer response. Using program INIT Operational meters (without metrological seal) can be directly with the operator changed to the following meter functions: Change of the total amount of liquid passed through Analog output set to the desired range: 20mA or 4 20mA Assign the maximum current 20mA analog output any value of instantaneous flow rate Adjust the position of the decimal point for the total amount of liquid passed Turn on/off periodic cleaning of the electrodes after 24 hours (only for meters that are equipped with lubrication) This enables the program INIT connected to the meter by cable RS 232 port. RS 232 connector is located on top of the circuit board and is accessible by removing the top cover of the electronics housing. (It cannot be performed for meters where the top cover is metrological provided). Program INIT is not included in electromagnetic flowmeter Comet F. 10 of 10