Download - Calibration Procedure


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This manual is for informational purposes only. Eagle Research Corporation MAKES NO

WARRANTIES, EXPRESSED OR IMPLIED, IN THIS MANUAL.

XARTU, XARTU/1, XARTU/5, XA-Series. LDVI, RtPM, SCI, TALON, and Field Manager are either registered trademarks, or trademarks of Eagle Research Corporation in the United States and/or

other countries.

CALIBRATION PROCEDURE (MVDP) Multivariable Differential Pressure Transmitter with an XARTU/1

CONTENTS

INTRODUCTION ............................................................................................................................. 3

SAFETY CONCERNS ........................................................................................................................ 3 Atmosphere .............................................................................................................................. 3 Arcing ........................................................................................................................................ 3 High Pressure ........................................................................................................................... 3 Safety Gear ............................................................................................................................... 4

FIVE-VALVE MANIFOLD ................................................................................................................... 4 KEYPAD / DISPLAY .......................................................................................................................... 5 CALIBRATION METHODS .................................................................................................................. 6

STANDARD CALIBRATION METHOD .......................................................................................... 7

CONNECTING THE INSTRUMENT ....................................................................................................... 7 FUNCTION KEYS ............................................................................................................................. 8 CALIBRATING THE MVDP TRANSMITTER STANDARD METHOD .................................................. 9

Calibrating the Static Pressure STANDARD METHOD ........................................................ 9 Setting ZERO Static Pressure .......................................................................................................... 9 Setting SPAN Static Pressure ........................................................................................................ 10

Calibrating the Differential Pressure STANDARD METHOD .............................................. 11 Setting ZERO Differential Pressure ................................................................................................ 11 Setting SPAN Differential Pressure ................................................................................................ 12

MULTI-POINT CALIBRATION METHOD ..................................................................................... 13

OPENING MULTI-POINT CALIBRATION WITH FIELD MANAGER ....................................................... 14 CONNECTING THE INSTRUMENT ..................................................................................................... 16 CALIBRATING THE MVDP TRANSMITTER MULTI-POINT METHOD ............................................. 17

Calibrating the Static Pressure MULTI-POINT METHOD ................................................... 18 Setting ZERO Static Pressure ........................................................................................................ 20 Setting SPAN Static Pressure ........................................................................................................ 22

Calibrating the Differential Pressure MULTI-POINT METHOD ........................................... 24 Setting ZERO Differential Pressure ................................................................................................ 24 Setting SPAN Differential Pressure ................................................................................................ 25

RETURNING THE UNIT TO SERVICE ......................................................................................... 27


Introduction The Multivariable Differential Pressure Transmitter (MVDP), typically attached to the bottom of the XARTU field computer, will measure the pressures across an orifice flow plate, and provide the differential pressure it sees to circuitry for signal output. The MVDP also sends a static pressure value to circuitry as a separate signal out. These two signals are the primary components used in orifice flow calculations. Along with a separate temperature signal and other values, accurate corrected flow measurement can be accomplished. Proper calibration of the MVDP is therefore necessary to achieve dependable readings. Calibration Mode, a built-in component of the XARTU programming, allows the user to calibrate the analog inputs such as differential pressure, static pressure, and temperature. While operating in the calibration mode the RTU continues to update volume. The analog input value used for calculations is the value measured when calibration mode was initially entered. Once in calibration mode, the user can perform the following operations:

Calibrate zero only Calibrate both zero and span

XARTU/1 calibration is software based, eliminating the need for the laborious and time-consuming requirement of repetitive potentiometer adjustments, and thereby simplifying the field calibration procedures. Safety Concerns Atmosphere When working on or near pipelines carrying combustible gasses or liquids, exercise extreme caution. Make sure all ports, valves, and other fittings are securely sealed, and that no unintended leaks are present. Never smoke or use ignition sources or fire near pipe and process lines that are not purged.

Arcing In conjunction with the statement on Atmosphere, be cautious using tools that may create a spark when struck or dropped. It is recommended that you use non-arcing tools for the work, and that you wear clothing that does not easily hold a static charge. Another source of arcing is the connection and disconnection of cables and other wiring.

High Pressure Always exercise caution when working with high pressure lines and equipment. Never apply high pressure to a line until all fittings are secured, and you are at that point in the procedure requiring it. Upon completion of any steps requiring high pressure, purge the test lines before moving on to the next step.


Safety Gear It is recommended that eye protection be used when perfoming tests on equipment requiring the use of high pressure, and that ear protection be used during times when high pressures are being purged.

Five-Valve Manifold This procedure is based on the use of a Five-Valve Instrument Manifold. This device greatly improves control and convenience when using differential transmitters, and is strongly recommended. The High (upstream) side of the MVDP is typically to the left, as you face the front, with the low side at right. An example installation is shown below (note that your manifold may have a different appearance than that shown).

Figure 1 XARTU Typical Valving Arrangement


Keypad / Display This procedure is written around the use of: 1) an internal Keypad/Display, 2) an external Keypad/Display, or 3) Virtual Keypad included in the Meter Reader Software. If using a physical Keypad/Display, plug it into one of the I2C expansion headers as shown below at upper left.

Figure 2 XARTU/1 Processor Board Detail


Figure 3 XARTU Keypad Layout

Calibration Methods The MVDP transmitter may be calibrated using one of two methods: Standard Calibration Multi-Point Calibration

Standard Calibration has the advantage of being done using only a pressure source, calibration gauges, and a local keypad/display - eliminating the need for Eagles Talon or Field Manager program and a computer. It is accurate, but somewhat more laborious than when using Multi-Point Calibration. Multi-Point Calibration takes advantage of automated software controls to guide you through the procedure, reducing the chance of error and oversight, and providing a more efficient method for calibrating the instrument. Talon or Field Manager software on a local computer is required for Multi-Point Calibration. Both methods will be described in the following sections.


STANDARD CALIBRATION METHOD Connecting the Instrument NOTE: Though not necessary, it is recommended that a five-valve manifold be used both in regular service, and for calibration procedures. The following steps are based on the use of this manifold. CAUTION: If a five-valve manifold is NOT used to perform these procedures, AN EQUALIZED AND GAUGED TEST PRESSURE MUST BE APPLIED TO BOTH THE HIGH AND LOW INLETS OF THE MVDP UNIT FOR THE STATIC PRESSURE TEST!

1. Remove any electrical power from the RTU.

2. Using site valves isolate and disconnect any field pipeline connections from the 5-valve manifold.

3. Using suitable adapters, connect your pressure standard to the High side (typically the left side) of the manifold inlet port (SEE CAUTION ABOVE). Make sure all manifold valves are opened (full counter-clockwise), and that the pressure standard supply is of sufficient volume and pressure to accomplish the task.

4. The High and Low Side Shutoffs permit a path thru the manifold from the Inlet to the Outlet ports. The High and Low Side Bypass valves open a path from either side to a common center point, and to the Vent valve. The Vent valve permits exhaust of the common point to the atmosphere. With the Vent closed, and both Bypass valves open, the High and Low sides are tied together, and thus equalized. Either side may be independently isolated from, or opened to, Vent.

The Standard Calibration Method uses five primary buttons on the keypad for calibrating the DP, P and T process variables, plus the numeric keypad digits 0 9. When the RTUs calibration mode is entered, it will freeze the last analog sample of the process variables and continue to calculate volumes using those values until the calibration mode is completed or exited.


The five keypad buttons required for calibration are as described below: cal - Freezes the last process variable sample for calculation and places the unit into calibration mode. zero - Sets the Zero point in the calibration procedure. ent - Saves the current value or exits the current section of the procedure. span - Takes the user to the full-scale span point of the transducer being calibrated. esc - Takes the user out of the current calibration sequence and returns the unit to the run mode.

Function Keys The XARTU software permits the assignment of Function keys F0 F9 to facilitate quick access to such items as Differential Pressure (DP), Pressure (P), Temperature (T), and Volume (V). Typically F1 is assigned to Volume, F2 to Pressure, F3 to Differential Pressure, and F4 to Temperature in factory-installed configurations. If your company has standardized the RTU differently, please make the necessary substitutions as you work through this Calibration Process. If you have specific documentation you may wish to complete the Table below for future reference and use during Calibration Procedures.

Function Key Default

Function Key Our Company

Description

F0

F1 Volume #1

F2 Pressure #1

F3 Differential Pressure #1

F4 Temperature #1

F5

F6

F7

F8

F9

Figure 4 Function Key Cross-Reference Table

The XARTU /1 uses the five special keys plus the 0 9 numeric keys to accomplish all of the calibration tasks.


Calibrating the MVDP Transmitter STANDARD METHOD **CAUTION** Be careful in applying pressure to the unit under test! Assure that all fittings are securely made up, and that pressures applied are within the established limits of the transducer range. Have a quick method handy to shut off pressure in the event of a hazard or an overpressure.

Calibrating the Static Pressure STANDARD METHOD

Static Pressure is calibrated first. Begin by setting all valves as shown: Close (turn CW) both main Shutoff valves and the Vent valve. Open (CCW) both Bypass valves. This will assure that equalized pressure will be placed on both sides of the Differential Pressure element inside, and damage does no occur. CAUTION applying high pressure to the unit with either bypass valve closed can damage the differential element. NOTE repeatedly pressing the esc button on the keypad at any time will exit the calibration procedure.

Setting ZERO Static Pressure

1. Apply operating power to the RTU (see its Installation and Operating Manual).

2. Press Function Key F3 to display the live Pressure window (remember to consult your cross-reference table if different).

3. Apply full pressure to the High Inlet port, according to the established range of the MVDP.

4. Open the High Side Shutoff valve.

5. Check for leaks while allowing the unit to stress for about 45-60 seconds.

6. Close the High Side Shutoff valve, and Open the Vent valve.

7. Press the blue cal key on the units keypad to enter Calibration Mode. If the unit being calibrated requires a password, you must enter it now at the PASSWORD? prompt. The display will now alternate between CALIBRATING and the parameter label in this case PRESSURE #1.

8. Allow the reading to stabilize on the display and press zero on the keypad:

ZERO> XX.XX NEW?> .


9. XX.XX represents the current value of the parameter being calibrated.

10. On the keypad, type in 0.00 and ent (or simply ent) if 0.00 is already there. The display will show Calculating. Briefly, then display the new point.

Zero for the unit is now set, and you may proceed to the next phase.

Setting SPAN Static Pressure

1. Close the Vent valve on the manifold.

2. Check your calibration standard for a stable pressure representing the Span value of the MVDP being tested.

3. Slowly open the High Side Shutoff valve.

4. Allow the reading to stabilize on the display and press span on the keypad:

SPAN> XX.XX NEW?> .


6. On the keypad, type in (the span value) and ent (or simply ent if the correct value is already there). The display will immediately show the new point.

Note: Steps 4, 5, and 6 are only required once. If there is any doubt as to the accuracy of the span calibration it may be repeated as often as necessary. But only the most recent point will be saved upon completion of the calibration cycle.

7. To enter the storage phase of the procedure, press ent on the keypad. The unit will prompt,

ENTER TO ACCEPT CALIBRATION

8. Press ent again to accept the calibration, or esc to abort and not store the

calibration results.

9. Close the High Side Shutoff and open the Vent valve. Check the reading for Zero.

10. If Zero is off, begin the full procedure again, starting at Setting ZERO Static Pressure.

The Static Pressure part of the MVDP is now complete.


Calibrating the Differential Pressure STANDARD METHOD

Begin by setting all valves as shown: Close (turn CW) both main Shutoff valves and the Vent valve. Open (CCW) both Bypass valves. This will assure that equalized pressure will be placed on both sides of the Differential Pressure element inside, and damage does no occur. CAUTION applying high pressure to the unit with either bypass valve closed can damage the differential element. NOTE repeatedly pressing the esc button on the keypad at any time will exit the calibration procedure. The Differential Pressure value is typically measured in Inches of Water (in/H20). The use of a calibrated dead-weight tester can often be easier to work with than a high pressure standard.

Setting ZERO Differential Pressure

1. Press Function Key F2 to display the live Differential Pressure window

(remember to consult your cross-reference table if different).

2. Open the Vent valve.

3. Press the blue cal key on the units keypad to enter Calibration Mode. If the unit being calibrated requires a password, you must enter it now at the PASSWORD? prompt. The display will now alternate between CALIBRATING and the parameter label in this case DP #1.

4. Allow the reading to stabilize on the display and press zero on the keypad:

ZERO> XX.XX NEW?> .


6. On the keypad, type in 0.00 and ent (or simply ent) if 0.00 is already there. The display will show Calculating. Briefly, then display the new point.



Setting SPAN Differential Pressure

1. Using your pressure standard, apply full Differential pressure to the High

Inlet port, according to the established range of the MVDP. Use caution not to overpressure the unit.

2. Close the High Side Bypass valve. This restricts your standards pressure to the high side of the MVDP cell, simulating the differential pressure seen across a flowing orifice plate.

3. With the Vent valve still open, Open the High Side Shutoff valve.

4. Allow the reading to stabilize on the display and press span on the keypad:

SPAN> XX.XX NEW?> .


6. On the keypad, type in (the span value) and ent (or simply ent if the correct value is already there). The display will immediately show the new point.

Note: Steps 4, 5, and 6 are only required once. If there is any doubt as to the accuracy of the span calibration it may be repeated as often as necessary. But only the most recent point will be saved upon completion of the calibration cycle.

7. To enter the storage phase of the procedure, press ent on the keypad. The unit will prompt,

ENTER TO ACCEPT CALIBRATION

8. Press ent again to accept the calibration, or esc to abort and not store the calibration results.

9. Close the High Side Shutoff and open the High Side Bypass valve. Check the reading for Zero.

10. If Zero is off, begin the full procedure again, starting at Setting ZERO Differential Pressure.

The MVDP Calibration Procedure is now complete. Follow the last section in this booklet to put the unit back into service.


MULTI-POINT CALIBRATION METHOD

Fig. 5 Laptop-to-RTU Communications Connection

The Multi-Point Method is performed using Eagles Talon or Field Manager software. With the Multi-Point Method, the local RTU keypad and display are not needed in the same way as they were using the Standard Calibration Method (though it is often handy to watch the values as they are displayed locally). Keypad Function Keys ARE still used, as described earlier, to access Volume, Pressure, Differential Pressure, and Temperature. See the section on Function Keys.


Opening Multi-Point Calibration with Field Manager Note: Multipoint Calibration is not supported by all databases. Firmware version v1.01/19 or greater is required to run Multipoint Calibration on Honeywells that use the I2C bus. If using an RS485 / Modbus connected Honeywell, firmware version v4.01/28 or greater is required.

1. Start the Field Manager program on your laptop or host computer.

2. Click the Connect button at upper left, to establish communications with

the unit, and enter the Connection Type as Direct, select the proper communications port being used by your computer and the Baud Rate according to the unit.


3. The screen will acknowledge that it connected, and return you to the modified start screen.

4. Click on the Calibrate button to start the Calibration Wizard. 5. Enter your name and click on OK.

6. Once you click OK at the User Name Entry box the Maintenance Mode Configuration window appears. Read the information on this window, follow the instructions, and then select OK.


By clicking OK the unit will go into Maintenance Mode. This will freeze the inputs to the flow calculations. This would be the ideal time to isolate the site.

Connecting the Instrument NOTE: Though not necessary, it is recommended that a five-valve manifold be used both in regular service, and for calibration procedures. The following steps are based on the use of this manifold. CAUTION: If a five-valve manifold is NOT used to perform these procedures, AN EQUALIZED AND GAUGED TEST PRESSURE MUST BE APPLIED TO BOTH THE HIGH AND LOW INLETS OF THE MVDP UNIT FOR THE STATIC PRESSURE TEST!

1. Isolate using site valves, and disconnect any field pipeline connections from the 5-valve manifold.


2. Using suitable adapters, connect your pressure standard to the High side (typically the left side) of the manifold inlet port (SEE CAUTION ABOVE). Make sure all manifold valves are opened (full counter-clockwise), and that the pressure standard supply is of sufficient volume and pressure to accomplish the task.

3. The High and Low Side Shutoffs permit a path thru the manifold from the Inlet to the Outlet ports. The High and Low Side Bypass valves open a path from either side to a common center point, and to the Vent valve. The Vent valve permits exhaust of the common point to the atmosphere. With the Vent closed, and both Bypass valves open, the High and Low sides are tied together, and thus equalized. Either side may be independently isolated from, or opened to, Vent.

Calibrating the MVDP Transmitter MULTI-POINT METHOD **CAUTION** Be careful in applying pressure to the unit under test! Assure that all fittings are securely made up, and that pressures applied are within the established limits of the transducer range. Have a quick method handy to shut off pressure in the event of a hazard or an overpressure.


Calibrating the Static Pressure MULTI-POINT METHOD

Static Pressure is calibrated first. Begin by setting all valves as shown: Close (turn CW) both main Shutoff valves and the Vent valve. Open (CCW) both Bypass valves. This will assure that equalized pressure will be placed on both sides of the Differential Pressure element inside, and damage does no occur. CAUTION applying high pressure to the unit with either bypass valve closed can damage the differential element.

1. Click on the drop down box next to Calibration Item and select Pressure.


2. The initial Multi-Cal window opens. You may choose to perform a Validation or Calibration at this time. Select the items for Validation/Calibration.

o Select the Low Calibration Point field to change the low validation point if necessary, typically this would be 0.

o Select the High Calibration Point field to change the high validation point if necessary. This will be the max value that the transducer can read.

o Select the Number of Calibration Points field to change the number of validation points.

o Select the Barometric Pressure field to enter the barometric pressure when validating a pressure transmitter.

o Select the Pressure Mode (Cal Display Only) field to view the pressure validation/calibration in Gauge or Absolute pressure.

If you are calibrating a Honeywell transmitter, the wizard reads the predefined setup for the item to validate/calibrate from the RTU and automatically sets the parameters on the screen. The Press To Start window appears. The title of the window shows the fixed values DP (differential pressure), SP (static pressure), FT (flow temperature), and Rate (flow rate) that the RTU will use for calculations while in the calibration mode. The status area at the bottom of the window displays Waiting For Response from Remote Received OK! as the wizard continuously reads information from the RTU.


3. To start the calibration click on the Press To Start Calibration button.

Setting ZERO Static Pressure

Make sure the two manifold Bypass valves are open.

4. Apply full pressure to the High Inlet port, according to the established range of the MVDP.

5. Open the High Side Shutoff valve.

6. Check for leaks while allowing the unit to stress for about 45-60 seconds.

7. Close the High Side Shutoff valve, and Open the Vent valve.

8. When the pressure stabilizes back at zero, accept that value on the Calibration Wizard screen, and move on to the next step.

9. The item being calibrated will be highlighted yellow along the top of the window. The first value to be calibrated is the zero value. This is the lowest value that the device will be able to read. Make sure that no pressure is being applied and click on the Zero Adjust button to take the first reading.


10. Next the take calibration point window will appear. Click on the Take Point button then click on the Accept Point button.

NOTE: Hitting Enter three times will work the same as clicking on each button.

Note: If the user wishes to change the applied reference value then click on the Adjust Applied Value button and type in the new value. This can be done while taking each point.


Zero for the unit is now set, and you may proceed to the next phase. Setting SPAN Static Pressure

1. Close the Vent valve on the manifold.

2. Check your calibration standard for a stable pressure representing the Span value of the MVDP being tested.

3. Slowly open the High Side Shutoff valve.

4. Allow the reading to stabilize on the display and take the Span Adjust point on the Calibration screen (the program automatically selects Span after Zero is accepted).


5. Continue adjusting the pressure and taking readings according to the Applied Reference value at each point until all values have been taken.


6. Once all values have been taken click on the Save Calibration button. Once these values have been saved in the unit the window will go back to the main calibration view.

7. When done, close the High Side Shutoff valve, and open the manifold Vent.

The Static Pressure part of the MVDP is now complete.

Calibrating the Differential Pressure MULTI-POINT METHOD Setting ZERO Differential Pressure

1. In the main Calibration screen click on the Calibration Items drop down box and select Diff Press.

2. Make sure the high and low calibration points are correct and then click on Press To Start Calibration to begin calibrating the Differential Pressure.

3. Make sure no pressure is being applied and click on the Zero Adjust button to take the zero value.

4. Accept the zero value on the Calibration screen.



Setting SPAN Differential Pressure

1. Using your pressure standard, apply full Differential pressure to the High

Inlet port, according to the established range of the MVDP. Use caution not to overpressure the unit.

2. Close the High Side Bypass valve. This restricts your standards pressure to the high side of the MVDP cell, simulating the differential pressure seen across a flowing orifice plate.

3. With the Vent valve still open, slowly Open the High Side Shutoff valve.

4. Allow the reading to stabilize on the display and take the span point on the Calibration screen (the program automatically selects Span after Zero is accepted).


5. Continue to take each point until all points are taken.

6. Click on the Save Calibration button.

7. When done, close the High Side Shutoff valve, and open the High Side Bypass valve.

8. Check the reading for Zero.

9. If Zero is off, begin the full procedure again, starting at Setting ZERO Differential Pressure.

The MVDP Calibration Procedure is now complete. Follow the last section in this booklet to put the unit back into service.


RETURNING THE UNIT TO SERVICE With the calibration procedure now complete, the unit may be returned to service. Follow these steps:

1. Disconnect from Field Manager (if applicable)

2. Disconnect the communications cable (if applicable) from the unit, and secure the cap back on the MS connector.

3. Close both High and Low Side Shutoff valves.

4. Open both High and Low Bypass valves.

5. Close the manifold Vent valve.

6. Disconnect all tubing and fittings used for the Calibration Procedure, and connect all site process tubing and fittings to the Five-Valve Manifold.

7. Restore line pressures to the manifold by opening site pressure valves at the orifice.

8. Slowly open the High, then the Low Side Shutoff valves at the manifold.

9. Open the Vent valve and allow the system to purge for about 5 seconds, and then close the Vent valve.

10. Check all fittings for leaks, and correct if necessary.

11. Close both of the manifold Bypass valves to isolate the High and Low sides.

12. Check the Pressure reading F2 and DP reading F3 on the unit display to assure readings.

This concludes the sections on Calibrating the MVDP.

Download - Calibration Procedure

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