MSA Altair 4XR vs Altair io 4: Which Gas Detector Should You Rent?

Both are MSA four-gas monitors, both cover LEL, O2, CO and H2S, and both leave our shop bump-tested with a calibration certificate. The choice comes down to one question: do the readings need to leave the unit?

The short answer

Rent the Altair 4XR when you need a dependable long-shift instrument in one worker’s hand: roughly 24 hours of runtime, IP68 sealing, drop-test toughness, and worker-down alerts built in. Rent the Altair io 4 when the operation is complex or large-scale enough that someone away from the opening needs to see the readings live, the io 4 adds smart features and real-time connectivity for exactly that.

Side by side

	Altair 4XR	Altair io 4
Gases	LEL, O2, CO, H2S	LEL, O2, CO, H2S
Runtime	Roughly 24 hours on a charge	Confirm for your dates at booking
Durability	IP68, waterproof to 6 ft for 1 hour; MIL-STD-810G drop tested, 25 drops from 4 ft, survives incidental 25 ft drops onto concrete	Confirm current datasheet at booking
Operating temperature	-40 to +60 C	Confirm current datasheet at booking
Connectivity	None. Bluetooth was discontinued on the 4XR family in July 2022	Real-time connectivity to remote dashboards (MSA Grid)
Worker-down alerting	MotionAlert flags an immobile user; InstantAlert is a user-activated alarm	Alarms and readings shared live with the connected dashboard
Weight	224 g	Confirm current datasheet at booking
Day rate	See the 4XR product page	See the io 4 product page

Why the 4XR is the default rental

The 4XR is our hero unit for a reason. A roughly 24-hour runtime means one charge covers a long shift with margin, not a nervous glance at the battery bar after lunch. IP68 sealing and MIL-STD-810G drop testing mean a unit that has been down a wet manhole on a lanyard keeps working. And MotionAlert and InstantAlert matter on thin crews: the monitor itself flags an immobile wearer, and the wearer can trigger a deliberate alarm, both directly relevant when the topside is one attendant.

One thing the 4XR will not do is talk to your phone. Bluetooth was discontinued on the 4XR and 5X families in July 2022, so any pair-to-phone plan belongs on the io series.

When the io 4 earns its rate

The io 4 carries the same core four-gas coverage and adds the thing the 4XR deliberately lacks: real-time connectivity. On a complex or large-scale operation, multiple entries, a supervisor covering several openings, or a program built around a live dashboard, the io 4 streams readings and alarms off the unit so the topside sees what the entrant sees. It is the natural entrant monitor for the operator-with-a-screen model we cover in our remote attendant monitoring guide, and it slots straight into our Remote Attendant Visibility Kit.

If nobody on your job will ever look at a dashboard, the connectivity is a feature you are paying for and not using. That is most single-crew entries, and it is why the 4XR stays the default.

Either way, it arrives ready

Every detector we rent ships bump-tested and calibrated with a certificate, and you should bump test daily during the rental per manufacturer guidance. Reading a four-gas display is a skill, not a given, and it pairs with confined space entry training from our sister company OnSiteSafety. Not sure which unit your entry needs? Contact us with the space and the crew size and we will tell you straight.