If you are required to use a four gas monitor in the course of your work, you might be wondering how exactly they work and why they are necessary. The purpose of the monitor is to detect the presence of four different substances (such as volatile organic compounds or VOCs, toxic gases, combustible gases, oxygen and carbon dioxide). They are a must for environments where more than one substance is likely to be present.
The LCD display of the device provides visual feedback for the user, including: the sensor types, readings, alarm status, battery condition, and more. Each of the sensors is listed on the screen with the reading underneath, so you will be able to check on all conditions with a single glance. Symbols will appear when a particular sensor needs to be bump tested or calibrated. You will also be able to see the status strength of the wireless radio.
Keys & Interface
In addition to their labeled functions, the [Y/+], [MODE] and [N/-] keys act as “soft keys” that control different parameters and make different selections within the menus. At all times, the left pane corresponds to the [Y/+] key, the centre pane corresponds to the [MODE] key and the right pane corresponds to the [N/-] key. Any of they keys can be used to manually activate the display backlighting so that the screen can be read.
There are three different modes to choose from. In hygiene mode, sampling is continuous. You can also clear peak and minimum values at any time. In search mode, the four gas monitor samples only when you tell it to. You can also clear peak and minimum values whenever you want. In TVOC and benzene mode, sampling is done as a ‘snapshot’ (which means that the device does not continually monitor for this substance).
Make sure that the batteries are fully charged before using the monitor. There are three battery options available – standard duration rechargeable Li-ion, extended duration rechargeable Li-ion, and alkaline battery pack (which holds four standard AA batteries). You can charge the batteries using either the desktop charger or travel charger (which come with the device). Press down so that the device is firmly seated in the cradle.
To turn the monitor on, press and hold the [MODE] key. When it beeps and the display and LED alarm lights turn on, you can release the key. It may take a few minutes for the device to boot up, so give it plenty of time to warm up before heading into the field. To turn the monitor off, press and hold the [MODE] key. A five second countdown will begin. Hold the key down until it powers off. See the owner’s manual for bump testing and calibration instructions.
We hope that the information provided here has given you a better understanding of how four gas monitors work and why they’re so important for some environments. Being able to carry a single monitor that can detect up to four different substances is far more convenient than carrying around four different devices, so don’t take it for granted. Ensure that you perform regular bump tests and calibrations to keep it in tiptop condition.