The Danfoss AKS 4100/4100U liquid level sensor is designed specifically to measure liquid levels in a wide range of refrigeration applications. The AKS 4100/4100U liquid level sensor is based on a proven technology called Time Domain Reflectometry (TDR) or Guided Micro Wave. Danfoss AKS 4100/4100U liquid level sensors can be used to measure the liquid level of many different refrigerants in vessels, accumulators, receivers, standpipes, etc. The electrical output is a 2-wired, loop-powered 4 - 20 mA output signal, which is proportional to the refrigerant liquid level. AKS 4100/4100U in a cable version is suitable for HCFC, Non-flammable HFC and R717 (Ammonia), and differing lengths from 800 mm / 31.5 in. and up to 5000 mm / 197 in..Key Features:Approved and qualified by Danfoss for refrigeration applicationsOne product covering several probe lengths (cable version)A single product for all commonly used refrigerants (cable version)Cable version requires less top-end clearance for installation and serviceProven operation with all refrigerants in combination with oil.No need to clean cable version when fully covered by oil.The cable version is very compact and easy to handle, ship, install and use with different lengths and refrigerantsChanges of the liquid dielectric constant (εr) do not affect operation.Refrigerants:R134aR22R401AR402AR404AR407AR407BR407CR407FR409AR410AR421AR502R717R507A