Review: Forensics Detectors FD 101 Oxygen detector $165

Amazon Affiliate Link: https://amzn.to/4aGFaR4 Price as reviewed: $165 Oxygen Detector | OSHA Alarms | 2-Year Battery Life | 10ft Drop Test Pass | IP67 Waterproof | USA NIST Calibrated This personal Oxygen alarm has a hard plastic case, a very solid metal d-ring and clothing/belt clamp, and a loud alarm buzzer and red flashing light that goes off if the O2 level falls below 19.5% (or rise above 23.5%). It worked quickly in my tests (dropping it into a container with CO2), and the unit I reviewed had 22 months remaining on the (consumable) electro - chemical O2 sensor [according to the bootup display]. The claim is that the built in Lithium primary battery will last for the life of the unit, although I have not personally verified the 22-24 month "shelf life". If you regularly go to high altitudes, work in confined spaces, or near tanks of liquid nitrogen or CO2, having one of these can be a life saver. At less than $8 a month, it's a relatively inexpensive bit of insurance.