pump keep a constant flow rate?
The Apex series provide an exceptionally accurate and stable inlet volumetric flow rate using a patented (pending) method of Exhaust pressure control. The backpressure created by air exiting the pump to atmosphere is measured across a small orifice. Internal electronics convert this pressure signal to a volumetric flow rate. The Apex samplers provide direct volumetric flow control with a real time flow indication. An ‘all digital’ motor control drive circuit offers excellent flow control response (pump quickly settles at the selected flow even following sudden inlet pressure changes. Calibration stability is exceptional over changes in working temperature, atmospheric pressure and long-term ageing. Accuracy is <5% over range, <3% after calibration at selected flow.
