Calibration

Guidelines

Recommended gas mixture:
CO: 100 ppm balance N2
H2S: 25 ppm balance N2
LEL: 50% LEL or 2.5% by vol. methane balance air
O2: clean air, 18%

To ensure accurate calibration, use a premium-grade calibration gas. Gases approved by the National Institute of Standards and Technology (NIST) improve the validity 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 or a bump test.
Used sensor: 60 seconds / new sensor: 5 minutes
Calibrate the detector at least once every 180 days, depending upon use and sensor exposure to poisons and contaminants.
Calibrate the detector if the ambient gas varies during startup.
Calibrate only in a safe area that is free of hazardous gas
Do not calibrate the detector during or immediately after charging is complete.
The H₂S, CO, LEL and O₂ sensors can be automatically zeroed each time the detector is activated if the Auto-Zero on Startup option is enabled. Activate the detector in a normal (20.9%/20.8% O₂) atmosphere.
If a certified calibration is required, contact BW Technologies by Honeywell.
Calibration can be performed using either a 0.5 l/min regulator or a demand flow regulator.
The maximum hose length for calibration is 3 ft (0.9 m).

Warning

Calibration cylinders that are used with a demand flow regulator must meet the following maximum inlet pressure specifications:

Disposable cylinders 0-1000 psig/70 bar
Refillable cylinders 0-3000 psig/70 bar

BW recommends using premium grade calibration gases and cylinders that are certified to National Standards. The calibration gases must meet the accuracy of the detector.

Diagnostics Protection

The detector tests the ambient air (auto-zero) and the test gas that is applied (auto span) to ensure it meets expected values. Auto-zero sets the zero-gas level of the sensor. If the target gas is present, the zero level will be incorrect.

If excessive target gas is present, the sensor(s) will fail and an error message displays.

In auto span, an error message displays if the target gas does not meet the expected values.

Sensor(s) that fail to span retain the previous span value and do not continue the calibration process.

Connecting the Gas Cylinder to the Detector

Refer to the following procedures and Figure 6. to connect the gas cylinder to the detector for calibration.

Note

Read all of the following procedures before beginning calibration.

Caution

The maximum hose length for calibration is 3 ft (0.9 m).

1. Verify the calibration gas being used matches the span concentration value(s) that are set for the detector.

2. Attach a 0.5 l/min regulator or a demand flow regulator to the gas cylinder.

3. Connect the calibration hose to the regulator on the gas cylinder.

4. Begin the calibration procedures. Refer to the Calibration Procedure section.

5. When calibration is complete, disconnect the hose from the detector and the regulator.

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