Modus T Series Pressure Transmitters

The Modus T Series pressure transmitters feature no moving parts to wear out, reliable long term stability, and are virtually position insensitive. These differential pressure transmitters measure low pressures and feature low power consumption and a variety of analog signal outputs, with a wide selection of standard pressure ranges and electrical ratings available.

The Modus T transmitters are an excellent choice for many HVAC, process, and automation monitoring requirements. These pressure transmitters monitor: filter differential pressures, fan static pressures, clean room pressures, variable air volume systems, and velocity pressures. Modus Series T pressure transmitters have been used for bubbler level systems, leak detection, and in medical and analytical instruments.

Operation of the Modus T Series Pressure Transmitters

The pressure sensing element is a differential capacitance cell for pressure measurements ranging from 0.1 to 5 inches of water (25 Pa to 1.0 kPa), or piezoresistive (silicon) sensors for pressure measurements ranging from 5 inches of water to 10 inches of water (1.0 kPa to 2.5kPa).

The capacitance cell is capable of sensing very low pressures, negative or differential. A very light weight, responsive diaphragm within the cell deflects a small amount when a small pressure is applied. This deflection results in a change in capacitance which is then detected and amplified electronically.

The piezoresistive sensor is a solid state device designed in a Wheatstone bridge configuration. When pressure is applied to the device the resistance of the bridge changes by a small amount. This resistance change is converted to a voltage and amplified.

The span or zero adjustment is performed with a 20-turn potentiometer for fine resolution.