Comparing BW Max XT II, Quattro, MicroClip XL Monitors | Major Safety Skip to content

Tech Notes - Differences Between Max XT II, Quattro, & MicroClip XL Gas Detectors

When asked what are the differences between the popular Honeywell BW Max XT II, Quattro and MicroClip XL gas detectors, we usually answer with differences in features. In this post, however, we want to take you under the hood of the three gas monitors.

Our aim is to help you understand the differences from the perspective of our technicians. Under the hood, you will find that there are significant differences among these confined space gas detectors. These differences account for the varied pricing, service life, and the repairability of the monitors.



SR-X2V BW Honeywell Oxygen SensorThe first sensor that usually fails in any gas monitor is the oxygen sensor. Smartly, Honeywell BW uses the same oxygen sensor (O2) in all three detectors - SRX-2V. It's is not a micro sensor, but a full size oxygen sensor. This means it's much more reliable. In some cases, in can last up to three years.

Honeywell BW Toxic and Combustible SensorsThe combustible sensor (LEL), hydrogen sulfide sensor (H2S), and the carbon monoxide sensors (CO) are the same in both the Micro Clip XL and its more expensive cousin, the Max XT II. These three sensors are all micro sensors - smaller than your average sensor. They work a little differently than normal electrochemical sensors. In spite of their small size they do have a very good life span--in most cases they last over three years. Why use micro sensors in the more expensive Max XT II? If full size sensors were used, its price would be even higher. Moreover, the size of the monitor would be substantially larger.

Quattro SensorsThe LEL, H2S, and CO sensors in the Quattro are different from the Max XT II and the MicroClip XL. They are larger and contain more of the "stuff" that makes a sensor work - this makes them longer lasting. We haven't changed out one of these in the last six months. They are beasts!



All three gas monitors' cases are made of the same durable material. They provide excellent shock resistance and moisture protection. One significant difference among them is the screws and attachment posts used to hold the top and bottom cases together.

Gas Detector ScrewsThe MicroClip XL is held together with plastic screws (top screw in the picture). The Quattro and the Max XT II are secured with stainless steel screws (bottom screw). The attachment posts - the posts the screws thread into - are plastic in the MicroClip XL. In the Quattro and the Max XT II, the attachment posts are plastic reinforced with metal threaded sleeves.


Battery Pack

MicroClip XL Battery PackThe battery pack in the MicroClip XL is hard wired (soldered) to the circuit board. It can be changed, but given the labor required, it is not worth it. If the battery pack fails under warranty, no problem - it's fixed for free. However, if it fails after the warranty period, we rarely recommend replacing it.

Max XT II Battery PackThe battery pack on the Max XT II is a plug-in type and can easily be changed out. In fact, we'll often have salvaged battery packs that we can provide for only $20. We've never had a customer have to buy a brand new Max XT II battery pack.

In the above picture, you can also see the Max XT II's pump. It's ingenious. It is easily replaceable and does a great job of protecting the monitor from water intrusion. Like the Max XT II battery pack, we can often provide a salvage replacement pump for about $20.

The Quattro that we sell comes with an alkaline battery pack. The 3 "AA's" are easily changed out. Although it can be purchased with a rechargeable battery pack, the convenience of alkaline batteries is not worth the additional expense.



Max XT II DisplayAll three monitors use a liquid crystal display. The display makes contact with the circuit board with a standard zebra strip. Display problems are very rare. If they do occur it is most often due to the zebra strip - this is easily replaced from salvage at no charge (for the part). We also have replacement screens available from salvage. If you crack yours, don't worry. We'll take care of you.



It should be evident that the Max XT II and the Quattro gas monitors are the most serviceable and therefore the most repairable of the three. Virtually every part is replaceable. The MicroClip XL, aside from sensor replacement, is rarely worth fixing outside of its warranty period.

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