S 2 AM-SPS3 JOLA bar electrode

Description

With 2 AM-SPS3, the JOLA bar electrode signals via an electrode relay the presence of a liquid medium due to, for example, a burst pipe. Floor electrodes are designed for use in dry rooms.

S 2 AM-SPS3 with integrated galvanic isolation:

• prevents interconnection of electrode circuits
• prevents the formation of earth loops when more than one detector is connected to a common power supply circuit.

Conductive rod electrodes must only be used in normally dry environments. They can be installed from the top or the side. In both cases, ensure that the tips of the electrode rods are only slightly above the ground to be controlled.

The conductive rod electrodes S 2 M / PP -…, S 2 M / PVDF -… and S 2 AM -… are equipped with two separate electrodes in the form of two electrode rods: 1 control electrode and 1 ground electrode. As soon as the conductive liquid creates a conductive path between the two electrode rods, the switching state of the leak detector changes.

Conductive measurement principle

The principle of conductive measurement is used to detect electrically conductive liquids. Not suitable for the detection of electrically non-conductive liquids.

Electrically conductive liquids are usually aqueous solutions of salts, acids or alkalis. In water, the molecules of these substances separate into positive and negative ions, which give the aqueous solution its electrical conductivity. The conductive leak detector detects the presence of an electrically conductive liquid and then sounds an alarm.

The measurement process uses alternating current to ensure accurate response sensitivity and to prevent galvanic processes at the electrodes. The conductive leak detector shall have an integrated electronic evaluation unit with galvanically isolated circuits. This prevents the electrode circuits from interconnecting and forming earth loops if more than one of these leakage detectors is connected.

Reliable detection of liquids with poor electrical conductivity, such as condensate or demineralised water, is ensured by the factory-set sensitivity response of the conductive leak detector.

Features of the S 2 AM-SPS3

• design: leak detector with quiescent current / NC (interrupting)
• electrode rods: 2 316 Ti stainless steel rods; other materials (e.g. titanium, Hastelloy, Monel or tantalum) on request;
• Length: on request (measured from the sealing surface of the spigot)
• max. Length: 2.500 mm
• Spout: G1, stainless steel
• Electrical connection: three-wire connection via a triple terminal block for max. 2.5 mm² in PP connector head with cable entry M 20 x 1.5
• protection class: IP 54
• supply voltage: only for connection to extra low voltage SELV or PELV! (see datasheet)
• Energy consumption: max. 0.5 VA
• output: PNP transistor output wired via a 2 kΩ … 7,5 kΩ downstream input resistor; wire colour: black
• short-circuit protection: at transistor output, Ik < 30 mA
• switching condition without supply voltage: low signal
• switching capacitor for state detection is not activated: the output of the PNP transistor carries the directional supply voltage = high signal
• switching capacitor for state detection is activated: the output of the PNP transistor carries the directional supply voltage = low signal
• cable break control: control of cable breakage due to quiescent current
• galvanic isolation: only for connection to extremely low voltage SELV or PELV! voltage resistance > 500 V between the capacitor circuit and the supply circuit
• max. no-load voltage across the sensing capacitors: 5 Veff 600 Hz
• max. short-circuit current on sensing capacitors: 0.2 mA
• response sensitivity: approx. 30 kΩ or approx. 33 μS (conductivity)
• temperature range: – 20 °C to + 60 °C

For more technical information, please refer to the datasheet attached under the Documentation tab.

Example of the use of S 2 AM-SPS3: monitoring false floors in the server room using a cable electrode and a panel electrode in an adjacent room.

Welcome to the article ”Conductive Measurement of Liquids”