A range of compact, low cost pressure switches is now available ATEX-certified for use in Zone 0, Zone 1 and Zone 2 gaseous atmospheres. Impress Sensors' new 901 range is suitable for monitoring over-pressure, vacuum or differential pressure in both liquid and gaseous media, including aggressive media, in hazardous environments. The switches can be used to monitor fluid levels and filters, as well as excessive or inadequate pressure and pressure differentials in closed systems.
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, where the customer uses a scaled adjustment knob to alter the trip and reset pressure, without having to use a screwdriver.
A wide range of switch options is 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.
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.