RAM 4021 CO (CO) Monitor with Alarm ResetFeatures:Continuous CO (CO) monitor for compressed airRobust, easy to operate designIntegrated dew point measurement (if specified)Meets OSHA monitoring requirements for grade D breathing air AutoCal automatic calibrationAvailable in 'CE' marked modelsDryer control relays (DPX model only)User-adjustable alarm pointsDry contacts for remote horn and lightsInternal, case-mounted hornLCD displayNEMA 4X housingThree-stage filtering option for up to 8 usersThe RAM 4021 AutoCal series is the unit of choice where specific and accurate measurement of CO, O2 or dew-point levels are required. Designed to meet OSHA requirements for monitoring of Grade D respirable air, this unit is equipped with a reliable electrochemical sensor that accurately indicates the level of CO on an illuminated liquid crystal display. Adding versatility, this unit offers optional O2 or dew point sensors for applications where detection or measurement is needed.Calibration and maintenance are simple with our innovative AutoCal system. Additional features including alarm relay contacts, user adjustable alarm points, low flow alarm indicator and many more, make this unit an intelligent choice. The RAM 4021 is available in four models, the 4021 (CO), 4021-1 (CO and O2), 4021-DPX (CO and dew point levels) and 4021-PR (CO and additional relay to signal power loss to monitor, complies with newest NFPA regulation). All models may be purchased with or without airline filter systems.All GfG Instrumentation RAM Instruments satisfy the requirements of OSHA rule 29 CFR 1910.134 for CO monitoring. They will also monitor Grade E air, generally specified for breathing air in cylinders (SCBA).