Calibration

Calibration

Guidelines

When calibrating the detector, adhere to the following guidelines:

• Recommended gas mixture:
  CO: 100 ppm balance N₂
  H₂S: 25 ppm balance N₂
  LEL: 50% LEL or 2.5% for NA (2.2% for EU) by vol.methane balance air
  O₂: 18% by volume, balance N₂.
• To ensure accurate calibration, use a premium-grade calibration gas. Gases approved by the National Institute of Standards and Technology (NIST) improve the accuracy of the calibration.
• Do not use a gas cylinder past its expiration date.
• Calibrate a new sensor before use. Install the sensor, activate the detector, and allow the sensor to stabilize before starting calibration (used sensor: 60 seconds / new sensor: 5 minutes, for X3 O₂ stabilization takes 60 minutes.
• Calibrate the sensors at least once every 180 days, depending on use and sensor exposure to poisons and contaminants.
• Calibrate the detector if the gas readings varies during startup.
• Calibrate the sensor before defining the alarm setpoints.₈
• Calibrate only in a safe area that is free of hazardous gas in an atmosphere of 20.9% oxygen.
• Do not calibrate the detector during or immediately after charging is complete.
• The oxygen sensor can be automatically calibrated each time upon activation (if this feature is enabled). Activate the detector in a normal (20.9%/20.8% oxygen) atmosphere.
• Allow the detector to stabilize for 1 minute after activation before performing a calibration or bump test.
• If a certified calibration is required, contact BW Technologies by Honeywell.

Diagnostics Test

The detector tests the air (auto zero) and the span gas that is applied (auto span) to ensure it meets expected values. Auto zero sets the zero-gas level of the sensor.

Auto Zero: If target gas is present, the zero level will be incorrect and the sensor will fail. If a sensor fails, an error message displays.

Auto Span: If the target gas does not meet expected values, an error message displays.

A sensors that fails to span retains the previous span value, and does not continue with the calibration process.

Connecting the Gas Cylinder to the Detector

Refer to the following Figure 7., Table 11., and procedures to connect the gas cylinder to the detector for calibration.

Note

Wind currents may cause false readings and poor calibrations.

Table 11. Connecting the Gas Cylinder to the Detector

Item	Description
1	Calibration cap
2	Calibration hose
3	Gas cylinder with 0.5 ml/min regulator

Read the following steps (1-7) before beginning calibration.

1. Verify the calibration gas being used matches the span concentration value(s) that are set for the detector. Refer to Calibration Gas in Fleet Manager II.

2. Attach a 0.5 ml/min regulator to the gas cylinder. To perform an automated calibration, use a demand flow regulator and refer to the MicroDock II User Manual.

3. Connect the calibration hose to the calibration cap.

4. Connect the other end of the calibration hose to the regulator on the gas cylinder.

5. Refer to Calibration Setup to apply gas.

6. When calibration is complete turn off gas and disconnect the hose from the calibration cap and regulator.

7. Ensure the gas cylinder is stored according to the manufacturer