This is a flow type, so it is ideal for reading the instantaneous value.
In general, suction pumps are operated continuously with the sampling unit attached. However, if the substances to be sampled are collected with a filtering material, this increases the load and decreases the flowrate. The flowrate when the suction pump is in use is set using the flowmeter provided. Many of these flowmeters are marked with standard scales, and in order to maintain the accuracy of the suction air volume, they must be calibrated using a standard flowmeter or standard gas meter by attaching them at a flowmeter attachment position upstream of the pump, with a load comparable to typical usage conditions for the flowmeter provided. Use a standard flowmeter or gas meter ideal for the suction pump’s suction flowrate.

This is a float (area) flowmeter with a needle valve. This is ideal for measuring and adjusting the flowrate of small suction pumps.