Piezoresistive level probe PIEZO AS

for water2-wire4-20 mA

Overview
The PIEZO AS piezometric level probe is designed for prolonged immersion and continuous level measurement in demanding environments, including wastewater and surface water (rivers, lakes, canals, turbid waters). It features a flush membrane and a non-stick coating to limit fouling and ensure reliable readings.

Applications
Suitable for pumping stations, water treatment, wastewater treatment plants, lift stations and pump automation via control relays. Provides continuous level logging for monitoring and control.

Operating principle
The probe integrates a piezoresistive sensor that measures hydrostatic pressure from the water column above the probe. The pressure is converted to an electrical signal proportional to the liquid height and delivered as a 4/20 mA output.

Installation and fixing
The probe can be suspended using the cable sheath and fixed at the required depth with the FIXCAB accessory. For frequent removal, use a stainless steel support cable with an eyelet to lift the probe. Avoid clamps or tight fittings that could damage the cable and cause capillary ingress.

Electrical connection
The electrical connection must be placed in a non-hermetic junction box (internal pressure equal to atmospheric pressure) located outside the tank. The cable and its capillary can be extended with a standard signal cable. ATMI offers cable lengths adapted to avoid harmful splices.

Recommended accessories

• FIX-CAB: cable clamp for suspended probe fixation
• Junction box: for extension of the power cable with a standard signal cable
• Surge protector: overvoltage protection for transmitters and auxiliary equipment

Technical specifications

• Measuring range (full scale): configurable from 2 mH2O to 20 mH2O (full scale 20 mA, set at factory to requested value)
• Output signal: 4/20 mA loop (4 mA = 0 m; 20 mA = full scale)
• Power supply: DC 6 to 38 V
• Power consumption: equal to the loop current (mA)
• Measuring cell: piezoresistive, stainless steel 316L
• Hysteresis: 0.05 %
• Operating temperature: 0 °C to 40 °C
• Housing: stainless steel AISI 316L
• Cable: 2 conductors 0.22 mm², supplied standard with 10 m PU cable
• Weight: 370 g
• Dimensions: height 130 mm - diameter 25 mm