Pressure switch 903.10 for the lowest pressures and liquid levels
Wherever marginal gas pressures or liquid levels have to be determined quickly and positively, purely mechanical, membrane-controlled pressure switches are an economical sensing and switching solution. Built onto a dip tube, minimum and maximum levels can thus be detected rapidly and valves or pumps switched off and on or alarms triggered depending on the liquid level. Because the pressure gauge does not come in contact with the medium, this method of measurement is suitable for measuring liquid levels in the foodstuffs industry and beverage sector but it also tolerates slurries in industrial overflow basins or waste water treatment. More exact switching points at low liquid levels are also increasingly being demanded. To this end, Beck GmbH Druckkontrolltechnik engineering has now developed a pressure switch for marginal switching pressures.
The pressure switch 903.10 (Fig.) offers a permanently set trip pressure from 3 mbar up to 50 mbar which is supplied factory set to the desired value. This means it can even detect lowest gas pressures or liquid levels respectively from approx. 3 cm hydrostatic head. The standard switching differential of 1.5 mbar at the start of the range and 15 mbar at the end of the range with a switch point tolerance band of 10 %. The new pressure switch is equipped with a larger membrane area for this which reliably actuates the switch contacts even at the slightest pressures. This can switch with a resistive load up to 6 A / 240 VAC in AgNi execution or in the low voltage range up to 100 mA / 24 VAC or 30 mA / VDC in gold plated execution. Special designs are possible in AgNi up to 10 A / 240 VAC. The connections are AMP 6.3 x 0.8 mm spade terminals to DIN 46244. The pressure connection has likewise been updated in line with practical requirements and now has a combined hose (6.5 mm) and threaded nozzle (G1/4“) in resistant polyphenylene sulphide plastics (PPS) into which the damping orifices with 0.3 / 0.5 or 0.8 mm diameter can be inserted as required. The pressure switch is designed for over 10 million switching cycles and conforms to CE standards. It measures 57 mm in diameter, 70 mm in height including hose connector and can be installed quickly and securely with accessories such as fixing brackets or protective caps for protection classes IP54 and IP65.