How Do I Manually Calibrate the BW GasAlertMicro 5 Pumped Multi Gas Detector?

Our short video guide will walk you through the steps needed to manually calibrate your BW GasAlertMicro 5 Pumped multi gas detector.

To calibrate your gas detector, you’ll require an appropriate concentration of calibration gas, a length of tubing, the quick connect module which should be supplied with the unit, and an appropriate regulator.

The unit we’re using for our guide and video includes sensors for combustibles (LEL), oxygen, hydrogen sulphide and carbon monoxide, so the concentration of gas we’re using is a mix of 25 ppm h2s, 100 ppm co, 2.2% ch4 and 18% o2 in a balance of Nitrogen.

This particular Micro5 model also includes an integral pump so in this case we’re using a demand flow regulator.  Before you begin calibration ensure you are in an area free of hazardous gases and in an atmosphere of 20.9% oxygen.

Ensure one end of the tubing is connected to the regulator and the quick connect is attached to the other end.  Attach the regulator on the top of the gas bottle and your equipment is ready

To switch the unit on hold down the green power button until the countdown has completed.  The unit will perform a self-test and a pump-test.  To complete the pump-test briefly block the pump inlet when instructed to do so.  The unit will also display sensor information and last calibration dates before returning to normal measurement mode.

To enter calibration mode, hold down the blue circular button and the down arrow until the CAL countdown completes.  The Micro5 will then complete an AUTO-ZERO process to ensure that all of the active sensors are zeroed and that oxygen is at 20.9% before calibration is carried out.

Once this is complete the screen will show Apply span gas now to calibrate or press the up arrow to select sensors.  As we’re using a quad gas mix then we can proceed with attached the quick connect to the pump inlet.

Attaching this to the monitor will mean the gas is automatically drawn by the demand flow regulator from the cylinder.  You will see the sensors start to respond to the gas and a countdown will appear in the lower left of the screen.  When the countdown is complete and the span is complete the screen should display as Calibration Successful or All Valid Sensors Spanned.

You can now remove the quick connect from the inlet.  The Micro5 will then ask you to set the due dates and the gas alarms. Press the green power button two skip each of these and return to normal measurement mode.  Each sensor should display 180 days for the due date of next calibration if you have successfully

If you wish to view this guide in video form then visit our YouTube Channel.