FD-4D

Calibration of FD-4D

Summary:
A step-by-step tutorial on calibrating your FD-4D 4 gas monitor. 

Model: 
FD-4D

Calibration Frequency: 
At least every 12 months.

Calibration Kit Items Required:

  1. Calibration Gas (Multigas)
  2. Calibration Gas Regulator (C10)
  3. Tubing

▶️ Tutorial Video

 

✅ STEP 1: ZERO Calibrate CO, H2S, and EX to 0 ppm and O2 to 20.9% using Fresh Air.

  1. Power on your 4 gas detector and allow 2 minutes for stabilization in fresh air.
  2. The 4 gas detector may not read precisely 0 ppm for CO, H2S, or EX. If it does not, you will need to perform a zero calibration. Also, the O2 sensor may be a bit lower or higher than 20.9%. If so, undertake a 20.9% fresh air calibration for the O2 sensor, as explained below.
  3. To zero calibrate CO, EX, and H2S, press the left button and go to the Menu Screen.
  4. Select "ZeroCal" by pressing the right button on the MENU screen.
  5. Then press the LEFT button until you select the sensor you wish to ZERO calibrate.
  6. Then, press the right button to select and save. Press the right button again to OK save.
  7. Done. Repeat from step (5) similarly for other sensors (except O2).
  8. For the O2 sensor to read 20.9% in fresh air. Go to the Menu Screen by long-pressing the right button.
  9. Select "SpanCal" by pressing the right button.
  10. Enter passcode: 1111
  11. Then, using the left button to highlight the O2. Press the right button to confirm 20.9% then press the right button again to confirm Save OK.
  12. Long depress the right button to go back to the MENU screen.
  13. Done!
  14. This completes the zero calibration of the H2S, CO, and EX sensors and the calibration of the O2 sensor to 20.9%. 

✅ STEP 2: SPAN Calibration of CO, H2S, and EX LEL.

  1. Expose the 4-gas monitor to your calibration reference gas for 2 minutes or until the reading has stabilized. Use a flow rate of 0.5 LPM and connect the gas to the gas detector via the FD-4A calibration cap.
  2. Select "SpanCal" from the Menu Screen.
  3. Enter passcode: 1111
  4. Then, using the left button select the sensor to be calibrated. Default calibration levels are CH4: 50%LEL, CO: 200ppm, H₂S: 25ppm, O2: 20.9%. 
  5. Then press "ENTER" with the right button.
  6. Press the right button. It will allow you to modify these calibration levels to align with your applied reference gas. If you have the default gas levels, then simply press the right button until you confirm Save OK.
  7. Long-press the right button to go back to the MENU screen.
  8. Done!
  9. Repeat this process for other sensors.
  10. Once completed, the analyzer is span-calibrated, and the calibrated value is shown on the main screen. 

✅ STEP 3: Verification

  1. Allow the gas detector to stabilize in fresh air for 5 minutes, confirming the CO, H2S, and EX LEL are reading 0, and O2 is reading 20.9%.
  2. Expose the analyzer to the calibration reference gas to verify the calibration and detection repeatability. Expose for 2 minutes.
  3. If the gas detector reading is within +/- 2% F.S. of the calibration gas value, this is considered a PASS. For example, the FD-4D has a full-scale reading of 1000 ppm for the CO sensor. The unit was calibrated to a reference gas of 200 ppm. Then, a PASS range is +/- 20 ppm around 200 ppm. Therefore, a PASS is between 180 ppm and 220 ppm.
  4. Once verified, your unit is properly calibrated and ready for operation.
  5. Don't forget to document the calibration event in your gas analyzer log book. Place a reminder calibration date sticker on the unit for the next calibration event.