Applying Gas to the Sensors (Part 2)


We have just begun to take a look at the correct procedure for calibrating your GasAlertMicro 5. In this section, we will continue with this basic overview. Once again, it needs to be stressed that this is merely a textual guide. You will also need to familiarize yourself with the physical characteristics of the detector in relation to calibration. So, it is important to examine all of the figures and tables that can be found in your owner's manual. Now, let us continue with this section before moving on.


Removing the Single Gas Calibration Cap


If you refer to the picture on page 47 of your owner's manual, you will note that the cap contains both an inlet and an outlet. Using your thumb, you will need to press forward against both inlets for the cap to remove. It should simply “snap” out.


A Look at the Calibration Procedure


You will need to perform this task to set the previously mentioned alarm setpoints. Remember that during any time of this task, you can press the main power button to bypass the calibration.


Before beginning, it is important to recall that the calibration gas must match the span values which are set for your unit. Failure to do so can result in an incorrect calibration and a potentially dangerous situation. Take a look at the section in the manual entitled Span Gas Values to verify this. Finally, only perform a calibration in an atmosphere that is 20.9% oxygen by volume.


You will need to press and hold both the clear push button and the down arrow simultaneously until your LCD screen reads “starting calibration”. The unit will also beep, vibrate and the LED lights will flash. Next, the unit will enter into the aforementioned auto zero mode. Likewise, this will flash as an icon on the display screen. The oxygen sensor will also be zeroed during this process. Different units may display this information on the LCD screen a bit differently. Finally, never apply any calibration gas during the auto zero process; this will lead to a failure.


Auto Zero CO2 Calibration (for GasalertMicro 5 IR)


With this device, you will need to proceed to step five in the auto span process (refer to the owner's manual in this case). For these models, a separate auto zero will be performed on the carbon dioxide sensor. You will be given a choice as to whether or not to perform this task (it is always recommended to auto zero all sensors). If you choose to perform this test, you will be asked to apply the relevant amount of carbon dioxide. However, it is important to state that you will need to apply NITROGEN to auto zero the unit as opposed to carbon dioxide. For approximately, thirty seconds, the auto zero icon will flash until the unit has correctly balanced itself.


We will continue to look at this process in the following section. Recall, always refer back to the owner's manual for any and all questions in regards to the calibration or the auto zero procedures.