Beck´s 901, 903 and 981 family of pressure switches and sensors

Wherever low or medium-high gas pressures or liquid levels have to be controlled with high reliability and fast response time, purely mechanical, membrane-controlled pressure switches are a very sensible choice. Built onto a customer configurable and process adaptable pressure port means that pressure medium level changes can be detected very fast. Thereby valves or pumps can be switched on or off and alarms can be triggered depending on the level. Because the pressure gauge does not come into contact with the medium, this technology is suitable for measuring liquid levels in the food and beverage sector, but also tolerates slurries in industrial overflow basins or waste water treatment facilities for instance. The Beck 901, 903 and 981 product family of pressure switches and sensors offer a large range of pressure levels for controlling and detection, configurable pressure ports, high accuracy and - new to the market - sensors with standardized analog output signal.

The basic 901 pressure switch has a proven track record for multiple industrial applications. It can be configured within 5 different pressure ranges or pressure differentials (settings from 5 mbar to 12 bar, including vacuum, are provided). It is delivered in many standard and customer specific configurations from a large selection of different membrane materials, pressure port designs and electrical connections. The 901 can switch a resistive load of up to 10 A / 240 VAC or up to 100 mA / 24 VAC or 30 mA / 24 VDC in the low voltage range. The electrical connections are AMP 6.3 x 0.8 mm spade terminals according to DIN 46244. The pressure switch is designed for over 10 million switching cycles and conforms to CE standards.

For a more precise switching at low liquid levels, Beck has developed the 903 pressure switch for low pressures. The 903 offers a switch pressure between 3 mbar and 50 mbar which is factory set to the desired value. This means it can detect very low gas pressures or liquid levels with a resolution better than 3 cm. The standard switching differential is as low as 1.5 mbar at the lower pressure switch settings and 15 mbar at the upper pressure switch settings. In comparison to a standard 901 pressure switch, the new 903 has a much larger membrane area which reliably actuates the switch contacts at very low pressures. Its dimensions are 57 mm in diameter, 70 mm in height including hose connector. For fast and secure installation accessories such as fixing brackets or protective caps for protection classes IP54 and IP65 are provided.

For more advanced sensing schemes, while still maintaining the excellent properties of the standard 901 configuration, Beck has developed the 981 pressure sensor with a normalized output of 4-20 mA or 0-10 VDC. Thus, the 981 sensor can interface directly with PLC control units and the pressure can be measured continuously. The 981 can replace the standard 901 pressure switch offering more value in the monitoring of pressure levels to the customer. The 981 safely works under the same conditions as both the 901 and the 903 pressure switches. The first version released to the market has a measurement range from 0 to 150 mbar. The pressure port configuration is almost identical to that known from the standard 901 pressure switch. The supply voltage needed for operating the sensor is 24 VDC. For the supply voltage and the normalized output, a M12, 4-pole connector is used. The membrane selection for the media separation is identical to the membrane selection for the 901. The 981 is therefore very well suited for pressure sensing in aggressive gas and liquids.