Gas flow meters of the M and V series use two of the best-studied physical properties of gases to measure flow: Viscosity and Pressure. Differential pressure measurement, across a laminar flow element, results in a flowmeter that is inherently linear. The flowmeters measure differential pressure within the laminar region, to achieve a typical turndown ratio of 100:1. Units are available with a very wide range of measurement, starting at 500 micro-liters per minute full scale to 1500 liters per minute full scale.

The "NON-THERMAL" M series Mass Gas Flowmeters use discrete Absolute Pressure, Differential Pressure, and Temperature sensor measurements within the laminar flow region to determine mass flow. The embedded microprocessor provides a software-based STP calculation compensated for pressure and temperature to standard conditions (1 atmosphere 25º Celsius). The M series address the limitations of thermal mass flow technologies, as there is no "Hot Wire" drift. The unit has an adjustable response time starting from 10 milliseconds. The dynamic display units show mass flow, volumetric flow, temperature and absolute pressure simultaneously. With the push button interface, the user can select the primary display, gas of interest (14 standard gases featured), adjust meter response time or tare the meter at zero flow. The optional battery pack makes for a powerful portable test and calibration tool.

Volumetric Gas Flowmeters of the V series are designed for applications venting to atmosphere, with constant and minimal/no backpressure. They do not include absolute pressure or discrete temperature sensors, which makes them an affordable alternative to mass flowmeters. As with the M series, the Volumetric flowmeters use discrete Differential Pressure sensor measurements within the laminar flow region to determine flow.