We use the MSA Altair 4x and Altair single gas detectors , Easy to use and so far service from sales company and MSA has been very good , The instructional dvd that comes with them was also very good , hope this helps
My name is Jason Fox and I am Product Line Manager for MSA's portable gas detection business. I have responsibilities for single gas detectors. MSA offers an ALTAIR and ALTAIR PRO versions of a CO single gas detector. The Altair unit has a non-replaceable battery and sensor and counts down from 24 (months). The detector can continue to be used beyond this period as long as it continues to pass the bump and calibration regimen. The detector will simply transition to a plus sign in front of the number of months and continue running until the battery drains. There is a multiple-stage low battery alarm, as outlined in our manual, to ensure adequate warning prior to end of battery life. I have one at my desk now that shows +17, meaning it has been constantly on for 41 months.
The ALTAIR PRO single gas detector has a replaceable battery and sensor and also performs datalogging such as TWA and STEL's (which may or may not be of interest to your department depending on the duration of a call). This detector also differs from the ALTAIR single gas in that the display always shows the gas reading versus the number of months remaining. That feature makes it nice for a FF to see what gas levels are present even below the low and hi alarm levels that you set.
Either product comes with a two-year warranty, which again is fully detailed in our manuals. Battery is inclusive in this for the ALTAIR model up to 18 hours of alarm time. The replaceable battery for the ALTAIR PRO can be purchased at a home improvement store.
If you have any questions, or would like to talk about the detectors, please send me an email at firstname.lastname@example.org.
Best wishes in your selection process! Jason
We use a 4 gas monitor by Drager that we have had pretty good success with. There are some cheaper single gas offered by HVAC suppliers. We have used one ( I think it was by EDI) that not only had the digital read out but also an LED that changed from green - yellow - red depending on the level detected which did help to idiot proof it some. However it did not offer a way to recalibrate or verify calibration.