Crowcon Gas-Pro IR [GPF-0011-EA-A] 4-Gas Confined Space Entry Monitor, CO (0-500ppm), O2, LEL IR CH4, PID, Non Pumped, With Flow Plate and Multi Region PSU.The infrared measurement gives improved reliability and measures gas in two different wavelengths: one that absorbs gas and the other does not. With little chance of being poisoned, the Gas-Pro IR personal multi gas detector is inherently safer and saves the need of regular and expensive pellistor replacement when used in likely contaminated environments. The Gas-Pro personal multi gas detectors are known for their simple use and functionality as well as easy testing and calibration. The Gas-Pro IR now completes the Gas-Pro range and gives greater flexibility for sensor selection in this 5-gas multigas detector. IR Technology: Infrared emitters within the sensor each generate beams of IR light . Each beam is of equal intensity and is deflected by a mirror within the sensor on to a photo-receiver, which measures the level of IR received. The “measuring” beam, with a frequency of around 3.3μm, is absorbed by hydrocarbon gas molecules, so the beam intensity is reduced . The “reference” beam (around 3.0μm) is not absorbed, so arrives at the receiver at full strength. User Friendly: Top Mount Display – makes it easy to read at a glance; Simple Single Button Operation – can be used whilst wearing gloves; Intuitive Functionality – reduces training time.  Adaptable: Monitor 5 Gases In Many Different Combinations; Pumped And Diffusion Solutions – offers multiple uses within one compact detector. Multiple Languages: Automatic Fail-Safe Flow Plate Recognition – takes away the pain of pre-entry testing; Specific And Unique Pre-Entry Check (PEC) Mode. Reliable: Reliable Lithium-Ion Battery – provides over 14 hr use from a 7.5 hr charge; Water And Dust Resistant To IP65 And IP67 – capable of withstanding harsh environments; Bump And Calibration Reminders – Full compliance.