The Model ASU-4 is an air sampling unit made for sampling air from 4 remote locations. The air sample is pulled by a heavy-duty reciprocating piston pump from 4 different locations into a manifold, and then routed to an Overhoff monitor for measuring the tritium concentration. This air sampling unit is for customers who want to use a single tritium monitor to measure the air from multiple rooms or locations. A programmable logic controller (PLC) is used to direct the airflow and can be customized for specific sampling applications. A separate purge line is included. Air can be sampled from up to 60 meters away.
The ASU-4 is housed in a wall-mounted NEMA-12 rated enclosure designed for continuous use. The enclosure has a hinged door that is furnished with a tempered glass window providing a view to the inside of the enclosure in order to visually check the display, air flow rate setting, and signal indicators. Information is shown on a programmable color LCD screen. The enclosure is double-hinged so that it can be easily opened for servicing.
Each inlet (5 total including purge line) includes an individual HEPA filter and flowmeter for adjusting flow rate. A differential pressure switch is used to detect and signal low flow rate.
|AIR FLOW RATE||3-25 LPM, Nominal Setting 10 LPM|
|OPERATING PRINCIPAL||Air sample is pulled by a pump from 4 different locations into a manifold then sent out through the exhaust line, which is sampled by a tritium monitor. Each flow rate from 4 inlet lines is adjusted by an air flow meter. There is a separate purge air inlet.|
|AIR MIXING MANIFOLD||Built from aluminum bar stock with 5 inlets and one outlet. Inlets are for 4 sample lines and 1 purge line. The outlet is connected to the pump inlet.|
|FLOW METER||Polycarbonate body flow meter, with stainless steel valve adjustable range from 1 to 25 LPM|
|FILTERS||Respirator cartridge type HEPA filter for all four sample inlets and one purge inlet. Connection fittings are 1/4” stainless steel Swagelok fittings.|
|PROGRAMMABLE LOGIC CONTROLLER||Panasonic PLC with relay outputs, powered by a 24VDC power supply includes RS-232 data output for remote capability|
|DIFFERENTIAL PRESSURE SWITCH||Diaphragm pressure switch used to detect low flow. Nominal setpoint is 5 LPM|
|PUMP||Heavy-duty Thomas reciprocating piston pump Model 2688CE44, 470W, 115VAC, 60 Hz|
|SOLENOID VALVES||Brass body, nitrile rubber seals|
|ENCLOSURE||NEMA-12 rated, 24” W x 22.56” D x 18.8” H [600mm x 573x 478mm]|
|WEIGHT||130 lbs. [59 Kg]|
|OPERATIONAL TEMPERATURE RANGE||10 – 40 °C|