U Series Non-Contact Ultrasonic Transmitter

Transcription

1 U Series Non-Contact Ultrasonic Transmitter Form 1035 This new SOR Ultrasonic Transmitter is a proven solution offering more flexibility and reliability than similar transmitters. With unique features, such as state-of-the-art programming, adjustable gain and a very powerful transmitter pulse, it provides consistent operation under conditions where other ultrasonics fail. The U Series is designed for use in harsh industrial environments with integral units of an explosion-proof design. The remote has a hard plastic electronics box that can be mounted up to 334 feet (100m) away from the process. All SOR transducers are encapsulated in rugged polypropylene enclosures. Theory of Operation Ultrasonic transmitters use pulses of high frequency sound to determine the distance to a target, such as a process liquid or solid. The transmitter measures the time it takes for the sound pulse to travel to the target and return as an echo. The distance can be calculated very accurately using the measured time and speed of sound in the atmosphere of the vessel. Pulses of ultrasound are continuously beamed toward the target. Ultrasonic echoes are received and processed, determining distance. Any condition that affects the size of the echo, creates false echoes or alters the speed of sound causes problems with this process. In industrial applications there are many situations that can do this. How successful a transmitter is depends on how well these conditions are handled. The following pages discuss the features of the U Series and how it addresses these difficult conditions.

2 Transmit Signal It is critical that an ultrasonic transmitter be able to receive a detectable echo from the process surface. This can be inhibited by many process conditions such as surface foam, dusty atmosphere and high concentrations of water vapor. Our philosophy is to provide a more powerful transmit pulse, at lower frequencies, along with sophisticated processing to overcome these obstacles and provide the best match of performance and reliability. We believe that a more powerful transmit signal gives a better chance of receiving an echo. But power alone won t solve all problems, so we combine this with lower frequencies. Low frequency sound penetrates difficult process environments better than high frequencies. However, high frequency instruments are less expensive to produce. So what is the right balance between performance and cost? Our solution is to automatically adjusted gain control, whereby the received echo gain is controlled by a self-adjusting amplifier circuit. The unit constantly monitors the strength of the process echo. If the echo is too small, the unit increases transmit gain until the echo is the proper size. If the echo is too large, the unit decreases transmit gain until the echo is the right size. This allows the unit to continually adapt to changing conditions. Automatically adjustable gain complements the high-power transmit signal and low frequencies to provide reliable, accurate measurement in difficult industrial conditions. Other transmitters use fixed gain and high frequencies, which results in unreliable operation in tough situations and sensitivity problems in normal service. Echo Recognition Every object within the transmit beam of an ultrasonic unit returns an echo. The trick is to decide which echo is correct. Installation location is critical for proper echo recognition. The transducer should always be mounted with a clear path to the process being measured. Physical intrusions on this path will create false echoes that must be processed. There are also mounting considerations based on the geometry of the vessel, such as domed roofs or cone-topped silos. Once the best installation location is chosen, there may be some false echoes. Other transmitters use static methods to handle these, such as placing a blank spot where false echoes occur, or storing an acoustical profile of the tank. These methods require draining a vessel and cannot account for changes in the process. Upper Limit Echo Strength Target Value Lower Limit Distance to Echo The gain is adjusted to keep the echo strength between the upper and lower limits. 2

3 The U Series uses echo recognition, a powerful automatic feature that allows the unit to pick the process out of all received echoes. In service, the largest echo will be from the process media, but the difference between it and a false echo may be very small. So the U Series runs all received echoes through a mathematical algorithm that exaggerates the difference in their sizes, making it very easy for the unit to pick out the largest echo and lock onto it. If the vessel conditions are such that this is difficult to do, the algorithm can be modified through the menus to customize the program for that particular application. Raw Signal Temperature Compensation and Velocity of Sound An ultrasonic transmitter must know the speed of sound in the atmosphere it s measuring through in order to be accurate. There are two factors that can affect the speed of sound; changing temperature and atmosphere composition. As the temperature of air changes, the speed of sound through it changes. The U Series incorporates a temperature probe in the face of the transducer to continually monitor the air temperature and compensate accordingly. There is no economical, reliable way to measure the speed of sound in other atmospheres while in service. Therefore, the U Series has a velocity of sound value that can be entered to account for these situations. This value is expressed as a ratio of the speed of sound in the atmosphere to the speed of sound in air. If the atmosphere will be continually changing in composition, then an ultrasonic transmitter is not the proper technology to use. Echo Strength Echo Strength Processed Signal Target Value Distance to Echo Measured Process Measured Process Distance to Echo The unit measures the first echo to cross the target value. 3

4 Applications The U Series is suitable for many applications found in industrial settings. The features previously discussed allow this product to adapt to many difficult situations. These same features make the U Series more reliable than other products in common applications. Some samples of applications for the U Series are given here. Water Vapor/Condensation Water vapors such as fog or steam can appear in any vessel with high water content. Condensation on the face of a transducer usually inhibits ultrasonic pulses. The U Series is able to reliably ignore condensation and water vapor. The powerful transmit pulse inhibits condensation build-up and provides the signal strength to pass through heavy fog or steam. These applications are found in water and waste water treatment, open sump pits, drainage ditches or any other open water source. Enclosed water applications can also have vapor and condensation problems. Some outdoor open vessel applications may have water problems due to local weather. Areas with frequent fog or high humidity can have water problems due to the ambient conditions. Difficult Vessel Geometry Vessel protrusions are present in an endless variety of applications. False echoes must always be accounted for by ultrasonics. Storage tanks with internal bracing, metal vessels with circumferential welds and wet wells with equipment inside are all examples of applications with many false echoes. Echo Recognition allows the U Series to be installed into these applications without emptying the vessel. In almost all cases the standard programming will be able to account for false echoes and still track the process reliably. Where it does not, the basic algorithm can be easily modified for that process. Bulk Solids Most solids applications have some degree of dust associated with them. In some cases, such as outdoor rock/sand piles, the dust may only be present when piling or removing material. Some silo or hopper applications may have heavy dust that settles quickly after moving material, although it usually takes a long time for dust to settle. Some applications such as fly ash silos may continuously have various levels of dust in the air. The U Series automatically adjusts to these conditions on a continuous basis. Whether solids are stored in a silo, hopper or on the open ground they will pile up in a cone shape. This is true with rough solids such as coal or crushed rock, and fine solids such as fly ash or carbon black. When solids are unloaded from the bottom they form an inverted cone. This change causes great difficulty with transducers that have to be aimed. Solids applications such as pile profiling, hopper inventory or silo measurement are common in many diverse industries, and aiming transducers is a problem for them all. The U Series eliminates these problems, as it does not require aiming for solids. 4

5 Applications Transducer Selection The transducer is the portion of the U Series that produces the transmit pulse and detects returned echoes. Transducers have a fixed frequency that determines the distance it can measure and how various process conditions affect it. Lower frequencies have longer ranges and are more immune to conditions such as dust, foam and water vapor. Higher frequencies have shorter blanking distances and lower cost. U Series transducers are selected based on the range to be measured, the media type to be measured and the expected vessel conditions. The guidelines on this and following pages should be used to select the proper transducer for your application. Blanking Distance All ultrasonic transmitters have a blanking distance in which they cannot reliably read process level. The blanking distance should be accounted for when selecting a model. Measurement Range The maximum measurement range under ideal conditions is given. The type of media being measured and the process conditions modifies the measurement range. Process Conditions Certain conditions such as dust can reduce the effective range of the U Series. Consult the factory for guidance when heavy dust, foam or condensation are expected. Transducer Frequency 30 khz 20 khz 10 khz 5 khz Solids Range Maximum Blanking 18" 0.45m 24" 0.6m 48" 1.2m 60" 1.5m Liquids/Slurry Range 10 ft. 3m 33 ft. 10m 33 ft. 10m 65 ft. 20m 100 ft. 30m 260 ft. 80m 260 ft. 80m 5

6 Features Technology Comparison The chart below shows how the U Series stacks up against other technologies and other ultrasonic products for industrial applications. Application Condition U Series Other Ultrasonics Radar RF Capacitance Differential Pressure Laser Easily selected for liquids, slurries or solids A B B C X A Changing dielectric constant A A B X A A Changing specific gravity A A A A X A Dusty atmospheres A C C A X C Water vapor (steam, fog, condensation, etc.) A C C A A X Long measuring ranges (over 100 feet) A B B C C A Poor surface conditions (foam, etc.) A C A B B X High Turbulence A B B C A B Vessel Intrusions A B B B A A A = Excellent B = Average C = Poor X = Not Recommended Features and Benefits The U Series transmitter has been designed to supply safe, reliable operation in many demanding conditions. It is easy to install, has many automatic features, and provides superior application flexibility and cost-effective installation. Non-contact sensing. No concerns with coating, mixers, etc. Powerful transmitted pulse for greater penetration and flexibility Automatically adjusted gain continually adapts to process conditions Echo recognition allows automated false echo handling Superior application flexibility dust, foam, condensation, angle of repose are automatically compensated Process flexibility field selectable for liquids, solids or slurry service Both AC and DC power supplies can be used at the same time backup power can be run along with primary power 6

7 Features Product Specifications - Electronics Operating Voltage 110VAC Version 220VAC Version Power Consumption 24 VDC Power Supply 10 W 110/220 VAC Power Supply 10 VA VDC and/or VAC VDC and/or VAC Relay Output Integral Version 2 Form C (SPDT) contacts rated 240 VAC Remote Version 4 Form C (SPDT) contacts rated 240 VAC All relays have independently adjustable deadbands. Analog Output Electronic Accuracy 4-20 ma invertible to 20-4 ma (700 ohm) ±0.25% of maximum range Agency Approvals CSA Process Control Equipment - Hazardous Locations Class I; Groups B, C, D; Class II; Groups E, F, G Class III LCIE Pending CSA/FM Pending CENELEC Pending Remote Cable Length <100m (334 feet) Remote Cable Type TYCAB DMC or Carol Cable C0784 Memory Electrical Connections Maximum Operating Pressure Operating Temperature Integral Unit Remote Electronics Remote Transducer Non-volatile with >10 years retention 2 x 3/4-inch NPT(F) on integral units. 15 psig (1.0 BAR) -40 F (-40 C) to 140 F (60 C) -40 F (-40 C) to 140 F (60 C) -40 F (-40 C) to 140 F (60 C) Product Specifications - Transducers Transducer Model Maximum Maximum Maximum SPL* at 3 ft. (1m) SPL* at 3 ft. (1m) (Frequency) Blanking Liquid/Slurry Solid/Powder in front of transducer to side of unit Distance Range Range A (5 khz) 60 inches 260 feet 260 feet 137 db 113 db (1.52m) (80m) (80m) B (10 khz) 48 inches 260 feet 100 feet 138 db 105 db (1.22m) (80m) (30m) C (20 khz) 24 inches 65 feet 33 feet 132 db 108 db (0.61m) (20m) (10m) D (30 khz) 18 inches 33 feet 10 feet 129 db 102 db (0.46m) (10m) (3m) *All values unweighted db (Lin) Peak measured with standard focusing cone. 7

8 How to Order Model Selection The U Series is selected as two separate model numbers one for the electronics package and one for the transducer. The transducer selection is limited, based on the electronics package selected. Therefore, the electronics should be chosen first. Sample Electronics Model Number U 71-CL7J-ZZ-PP Ultrasonic Level Transmitter; line-powered integral unit; weathertight and explosion-proof housing with window; 110 VAC and/or 24 VDC power supply with 4-20mA and two discrete outputs; all associated agency listings and a paper supplemental tag. Mounting Housing NEMA 4/explosion proof with window (integral only) NEMA 4/explosion proof without window (integral only) NEMA 4X with window (remote only) NEMA 4X without window (remote only) 3 Integral 1 Remote 3 4 C D F P 5 L Level Measurement Level Measurement 6 Input Power VAC and/or 24 VDC VAC and/or 24 VDC 7 J Output Type 4-20 ma with discrete outputs 8 Agency Approvals* 00 None ZZ All associated agency listings (see page 7) 9 PP RR VV TT LF Accessories Paper tag Wired-on SS tag Fungicidal varnish on housing Riveted-on SS tag Used for 5 and 10 khz transducers Power Type 2 Line powered 7 Transmitter Type Ultrasonic 1 U U C L 7 J - ZZ - PP Model Number *Match sensor approvals to electronics approvals to maintain the agency listing integrity. 8

9 How to Order Sample Transducer Model Number BCP-3A-ZZ PP Integral-mount transducer; 20 khz line power; polypropylene sensor; 3-inch NPT(F) process connection; no transducer cable and paper supplemental tag. 13 Process Connection Size 3 3-inch (standard on 20/30 khz transducers) 4 4-inch (flange only) 6 6-inch (flange only) F 8-inch (flange only) G 10-inch (flange only - standard on 5/10 khz transducers) Sensor Material of Construction Polypropylene sensor body 12 P 14 A C Process Connection Type NPT pipe thread (3-inch size only) 150# ANSI style FF flange (material to match sensor material) Transducer Range Agency Approvals* 5 khz A 10 khz B 20 khz C 30 khz D 00 None ZZ All associated agency listings 16 Cable Length Transducer Type Integral mount Remote mount 10 B R XXX.X Remote transducer cable length in feet (334 ft. maximum) Integral transducer (no cable required) 17 FC PP RR Accessories Focusing cone for 20/30 khz transducers (minimum 4-inch flange on 20 khz) Paper tag (remote only) Wired-on SST tag (remote only) B C P - 3 A - ZZ PP Model Number *Match sensor approvals to electronics approvals to maintain the agency listing integrity. 9

10 Dimensions Remote Electronics 30 khz Transducer Cable Length per Customer Sensor Name Tag Electronics Name Tag 1-inch BSP Nipple inch NPT Process Connection Optional 150# FF ANSI 3-inch NPT Process Connection 1/4-20 Mounting Connection (Type 4) Optional 150# FF FC Option Detail Remote Electronics 20 khz Transducer Cable Length per Customer Sensor Name Tag Electronics Name Tag 1-inch BSP Nipple inch NPT Process Connection Optional 150# FF ANSI 1/4-20 Mounting Connection (Type 4) # FF Flange Connection per Order FC Option Detail Dimensions = mm inches 10

11 Dimensions Remote Electronics 10 khz Transducer Electronics Name Tag /4-20 Mounting Connection (TYP 4) Cable Length per Customer 1-inch BSP Nipple Sensor Name Tag inch 150# FF Remote Electronics 5 khz Transducer Electronics Name Tag 1/4-20 Mounting Connection (TYP 4) Cable Length per Customer 1-inch BSP Nipple Sensor Name Tag inch 150# FF Dimensions = mm inches 11

12 Dimensions Integral Electronics 30 khz Transducer 3/4-inch NPT Conduit Connection Both Ends Opposite End is Plugged Sight glass cover shown. Subtract 0.52 inches (13.7 mm) from this dimension for housings with blind covers inch NPT Process Connection FC Option Detail Optional 150# FF Flange Connection inch NPT Process Connection Optional 150# FF /4-inch NPT Conduit Connection Both Ends Opposite End is Plugged Integral Electronics 20 khz Transducer FC Option Detail 3-inch NPT Process Connection # FF per Order Optional 150# FF Sight glass cover shown. Subtract 0.52 inches (13.7 mm) from this dimension for housings with blind covers Dimensions = mm inches

13 Dimensions Integral Electronics 10 khz Transducer /4-inch NPT Conduit Connection Both Ends Opposite End is Plugged 10-inch 150# FF Sight glass cover shown. Subtract 0.52 inches (13.7 mm) from this dimension for housings with blind covers. Integral Electronics 5 khz Transducer /4-inch NPT Conduit Connection Both Ends Opposite End is Plugged 10-inch 150# FF Sight glass cover shown. Subtract 0.52 inches (13.7 mm) from this dimension for housings with blind covers. Dimensions = mm inches 13

14 Worksheet Applications Worksheet for Non-Contact Ultrasonic Transmitters Company Address Contact Name Phone FAX Rep Company Rep Contact General 1 Tag Number 2 Application Level / Open Flow 3 Function 4 Area Classification Hazardous / Non-Hazardous 5 Agency Approval Sensor 6 SOR Transducer Model 7 Process Connection Type NPT / 150# ANSI Flange 8 Process Connection Size 9 Focusing Options Standard / High-Gain 10 Process Wetted Materials Polypropylene / Teflon 11 Measured Range ft / m 12 Mounting Distance from Sidewall ft / m 13 Mounting Distance from Filling Port ft / m Vessel 36 Vessel Materials 37 Vessel Diameter ft / m 38 Vessel Height ft/m 39 Vessel Top Open / Sloped Domed / Flat 40 Vessel Bottom Conical / Flat 41 Filling Method Pneumatic / Gravity Other 42 Noise In or Around Vessel Yes / No (describe below) 43 Obstructions Inside Vessel Yes / No (sketch below) Application Notes Electronics 14 SOR Electronics Model 15 Location Integral / Remote 16 Remote distance ft / m 17 Enclosure Class 18 Conduit Connection 3/4-inch NPT 19 Power Supply VAC Line (Line is also VDC) VAC Line 20 Transmitter 4-20mA / 20-4mA 21 Number of Setpoints 22 Switching Type Relay / 8-16 ma Process 23 Media Name Conditions 24 Media Type Liquid / Slurry / Solid 25 Density 26 Particle Size 27 Coating/Buildup Yes / No 28 Foam Yes / No 29 Agitation Yes / No 30 Vapors (not air) Yes / No 31 Pressure Maximum 32 Pressure Normal 33 Temperature Maximum 34 Temperature Normal 35 Ambient Temperature Instructions 1. Complete the company and contact information. 2. Fill out the form above as completely as possible. 3. In boxes where an option is given, cross out the undesirable choice(s). 4. In boxes that are blank, fill in the appropriate information. Please remember to use engineering units where required. 14 Application Sketch 5. In boxes with only one choice, this is the standard feature for the product. 6. Provide any additional details in the Applications Notes section. 7. Provide a sketch of the application showing vessel shape, size, mounting location and any internal obstructions in the Applications Sketch section. 8. Fax completed sheet to SOR:

15 Notes 15

16 Process Instrumentation SOR INC West 105th Street Lenexa, Kansas Phone Toll Free Fax Form 1035 (3.02) Printed in U.S.A.