Analog output calibration - Johnson Controls - LIT-12014081 - RA-1270 - Airflow Measuring Station - AFMS

RA-1270 Advanced Thermal Dispersion Fan Inlet Airflow and Temperature Measuring System Technical Bulletin

Brand
Johnson Controls
Product name
AFMS
Document type
Technical Bulletin
Document number
LIT-12014081
Revision date
2022-08-04
Language
English

Procedure

Analog output calibration enables calibration adjustments of the RA-1270 host monitor analog outputs 1 and 2.

Table 1. Analog output calibration configuration selections and options
Configuration selections Configuration options
Output 1 mA Offset Set the mA offset of output 1 from -2 mA to 2 mA.
Output 1 mA Low Span Select the low span of output 1 from 1 mA to 4 mA. The low span must be lower than the high span.
Output 1 mA High Span Select the high span of output 1 from 1 mA to 20 mA. The high span must be higher than the low span.
Output 2 mA Offset Set the mA offset for output 2 from -2 mA to 2 mA.
Output 2 mA Low Span Select the low span of output 2 from 1 mA to 4 mA. The low span must be lower than the high span.
Output 2 mA High Span Select the high span of output 2 from 1 mA to 20 mA. The high span must be higher than the low span.
Design Range Low Set the design range low for outputs configured for flow from 0 fpm to 10,000 fpm, or equivalent volumetric flow. The design range low must be lower than design range high.
Design Range High Set the design range high for outputs configured for flow from 0 fpm to 10,000 fpm, or equivalent volumetric flow. The design range high must be higher than design range low.
Temperature Range Low Set the temperature range low for outputs configured for temperature from -29.2°F to 129.2°F. The temperature range low must be lower than the temperature range high.
Temperature Range High Set the temperature range high for outputs configured for temperature from -29.2°F to 129.2°F. The temperature range high must be higher than the temperature range low.
Output 1 Test Enables the user to test output 1 with the offset and span settings at 0%, 50%, and 100% output.
Output 2 Test Enables the user to test output 2 with the offset and span settings at 0%, 50%, and 100% output.

You can configure these settings with the RA-1270 host monitor mounted in its operating location or at a test bench in a calibration laboratory. Complete the following steps

  1. Set the analog output 1 parameter to None to keep the output from changing with flow or temperature.
  2. While in the Operator Menu, use UP or DOWN to scroll to Flow LPF > Output Cal Menu.
  3. Press ENTER to enter the Output Calibration Menu. The display shows Out1 mA Offset > Out1 mA Lo Span
  4. Select Out1 mA Offset and press ENTER. The display shows the Output 1 Offset value.
  5. Connect a digital multi-meter (DMM) set for the scaling of the analog output 1 across terminals 1 and 2 on the RA-1270 host monitor. The DMM reads a minimum value of 4.00 mA ± 0.01 mA, as determined in the output 1 span.
    Figure 1. Host monitor
    Note: Output is 1 mA to 20 mA and a load resistance should be in series with the DMM. To accomplish this, connect the actual process load or a resistor of similar value to the actual process load, 250 ohm minimum.
    WARNING
    • Failure to put resistance in series with output trips the internal solid state fuse protection.
  6. If the DMM reading is out of tolerance, use UP or DOWN to adjust the RA-1270 host monitor output for an acceptable DMM reading. Use single digit data entry from left to right to change the output 1 offset. When you press ENTER on the last digit, the DMM shows the adjusted output 1 offset.
  7. When you obtain an acceptable zero reading, scroll UP or DOWN and the display shows Out1 mA Offset > Out1 mA Lo Span.
  8. Select Out1 mA Lo Span and press ENTER. The display shows Out1 Lo Span and the mA value.
  9. Use UP and DOWN to scroll from 1 mA to 4 mA to set the low span. The low span must be lower than the high span. When the low span is set, press ENTER and the display shows Out1 mA Offset > Out1 mA Lo Span.
  10. Scroll DOWN to Out1 mA Hi Span and press ENTER. Display shows Out1 Hi Span and the mA value.
  11. Use UP and DOWN to scroll from 1 mA to 20 mA to set the high span. The high span must be higher than the low span. When the high span is set, press ENTER to confirm the setting.
  12. You can now reset the analog output 1 parameter to its previous value before the calibration process.
  13. Repeat Step 1 to Step 11 for RA-1270 host monitor analog output 2 and connect the DMM across terminals 3 and 4.
  14. When both analog outputs are configured and calibrated, next configure design range low and design range high. Scroll to display Out2 mA Hi Span > Design Range Lo.
  15. Select Design Range Lo and press ENTER. The display shows Design Range Lo and the value in CFM.
  16. Press UP or DOWN to adjust the design range low value. Use single digit entry, from left to right, and press ENTER after the final digit to confirm the value.
  17. Press UP or DOWN to scroll and display Design Range Lo > Design Range Hi.
  18. Select Design Range Hi and press ENTER. The display shows Design Range Hi and the value in CFM.
  19. Press UP or DOWN to adjust the design range high value. Use single digit entry, from left to right, and press ENTER after the final digit to confirm the value.
  20. The final design range to configure is the temperature range low and the temperature range high. Scroll to display Design Range Hi > Temp Range Lo.
  21. Select Temp Range Lo and press ENTER. The display shows Temp Range Low and the value in °F.
  22. Press UP or DOWN to adjust the temperature range low value. Use single digit entry, from left to right, and press ENTER after the final digit to confirm the value.
  23. Press UP or DOWN to scroll and display Temp Range Lo > Temp Range Hi.
  24. Select Temp Range Hi and press ENTER. The display shows Temp Range Hi and the value in °F.
  25. Press UP or DOWN to adjust the temperature range high value. Use single digit entry, from left to right, and press ENTER after the final digit to confirm the value.
  26. Press UP or DOWN to scroll and display Temp Range Hi > Test Output Ch1.
  27. Select Test Output Ch1 and press ENTER. The display shows Connected Device Will Be Affected.
  28. Press ENTER to confirm the warning prompt. Press ESC to return to the Output Cal Menu without affecting the output. When confirmed, the display shows Output Percent and the % value.
  29. Press UP or DOWN to adjust the channel output percent between 0%, 50%, and 100%. 0% outputs the channel low span and 100% outputs the channel high span.
  30. Press ESC to return to the Output Cal Menu. Returning to the menu or normal operating screen stops all test output and returns the outputs to normal operation.
  31. Press UP or DOWN to scroll and display Test Output Ch1 > Test Output Ch2.
  32. Select Test Output Ch2 and press ENTER. Repeat Step 27 to Step 30 to test the output for channel 2.
  33. Press UP or DOWN to scroll to Exit this Menu and press ENTER to exit to the Operator Menu.
  34. Alternatively, press ESC to return to the Operator Menu.