Greyline’s SLT 5.0 continuously measures, displays, transmits and controls liquid level in storage tanks and pumping stations. It also measures the open channel flow through any flume or weir. calibration is simple with the built-in 5 button key pad and the isolated 4-20mA output transmits level or flow. there are 2 built-in programmable control relays. the optional built-in data logger stores 2 million points and the data is easily downloaded to a memory stick via the built-in USB port.