Crowcon Gas-Pro IR [GPP-0007-EA-A] 4-Gas Confined Space Entry Monitor, NH3, O2, LEL IR CH4, PID, 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.