Compact, low-cost pressure switches are ATEX-certified

The new 901 range of switches are suitable for monitoring overpressure, vacuum or differential pressure in liquids and gases, including aggressive media, in hazardous environments. They can be used to monitor fluid levels and filters, as well as excessive or inadequate pressure and pressure differentials in closed systems.

These explosion-proof switches are useful for a range of explosive atmosphere environments, including those found in the nuclear, oil and gas, chemicals, pharmaceuticals, sewerage and food processing industries.

The switches are available in a factory-set version, in which the pressure setting and switching differential are set by the manufacturer, or an adjustable version, the 901 Prescal, that enables the customer to alter the trip and reset pressure via a scaled adjustment knob, without having to use a screwdriver.

Numerous switch options are available, including pressure connections in various materials, shapes and sizes. Customers can also select from a diverse range of materials for seals and diaphragms. All switches are intrinsically safe and have been categorised as Temperature Class T4 and Explosion Group IIB or IIC.

Sam Drury, Sales Director at Impress Sensors & Systems, comments: "Some of our customers need to monitor pressures in potentially explosive atmospheres. In the chemicals sector, for example, air mixtures and ignitable gases are commonplace and can cause explosions if a source of ignition is present. Therefore, industrial instrumentation devices such as pressure switches need to be protected accordingly. We are delighted to be able to offer these ATEX-certified sensors to the UK."

The factory-set 901 switch can be set according to the customer's specification at a fixed value between 5mbar and 12bar in the positive pressure range and between -5mbar and -900mbar in the negative pressure range. With the 901 Prescal switch, the switching pressure can be controlled using an adjustment knob. For process connections there is a choice of plastic or metal hose connectors or threaded connections, including BSP, NPT and metric standards.

For more information about the 901 switches, go to www.impress-sensors.co.uk/mech-pressure-switch.htm.