Purpose

Non-polarizable copper sulphate reference electrode ENES-1 is intended for generating electrolytic contact with the ground in the schemes to define efficiency of cathodic protection of underground metal constructions.
Features

ENES-1 includes ion-exchange membrane protected by grid cover. The membrane provides for the safety of electrolyte during the whole service life.

ENES-MS-2 includes two ion-exchange membranes.

Construction and schemes of both electrodes are similar.
Operating conditions

Electrode ensures reliable and stable operation in all microclimate regions under the following climatic conditions:
- the upper value of ambient temperature + 45 °C;
- the lower value of ambient temperature – 40 °C;
- the upper value of relative humidity 100% at +35%.

Electrode is erected in the ground with the output of wires to the control and measuring post. Electrode can be also applied as a portable device.

Specified operating time – not less than 100 000 hours.

Guaranteed service life – not less than 30 months.

Specified service life – 10 years.
Electrodes intended for export additionally meets the requirements RD1601.007-88
Construction

Electrode consists of:
- plastic case 3, filled with electrolyte 4;
- copper rod 5, connected by wire with tag 2;
- ion-exchange membrane 6;
- potential sensor 10 connected by wire with tag 1.

Potential sensor realized as a steel plate 25x25mm which is built in the plastic jack fixed on the electrode case.

Tag 2 is realized as a plug, tag 1 is realized as a pin jack.

	1 - Tag from potential sensor 2 - Tag from electrode 3 - Electrode case 4 - Electrolyte 5 - Rod 6 - Ion-exchange membrane 7 - Rubber gasket 8 - Nut 9 - Routing tracks 10 - Potential sensor 11 - Tag from braided screen
Fig.1 Non-polarizable reference electrodes ENES-1, ENES-MS-2

Technical data

Parameter	Standard
1. Intermediate resistance, kohm	0,1 - 15,0
2. Potential towards chlorine-silver electrode, mV	120±30
3. Length of wires, mm, not less than	2500*
4. Weight, kg2	2х0,75*
5. Keeping quality period before the start-up, years	3

Principle of operation

To measure potential difference between the pipeline and the electrode, voltmeter is used. It should have input resistance not less than 20 kohm/V and measuring ranges 3-0-3 or those ones close to the given above.
Positive terminal is to be connected to wire from electrode, negative terminal – to wire from pipeline (Fig.3). Instrument readings should be taken every 5 sec. Duration of measurement should be not less than 10 min. In the zone of influence of tram stray currents, readings are to be taken during the morning or evening traffic peak-hours.

If readings are taken in the zone of influence of electrified railway stray currents, duration of measurement should cover starting torques and electric train round transition time between two nearest stations.

Polarizing potential should be measures by means of devices containing current interrupter (Fig.4).

1 - Control and measuring post 2 - Wire from pipeline 3 - Wire from electrode 4 - Wire from potential sensor 5 - Pipeline 6 - Electrode case	7 - Potential sensor 8 - Carpet 9 - Connector 10 - Contact wire 11 - Braided screen
Fig.2 Electrode installation diagram

	1 - Pipeline 2 - Wire from pipeline 3 - Wire from electrode rod 4 - Wire from potential sensor 5 - Voltmeter 6 - Electrode 7 - Potential sensor 8 - Connector 9 - Contact wire
Fig.3 Scheme of measuring potential difference

	1 - Pipeline 2 - Wire from pipeline 3 - Wire from electrode rod 4 - Wire from potential sensor 5 - Instrument device 6 - Electrode 7 - Potential sensor 8 - Connector 9 - Contact wire
Fig.4 Scheme of measuring polarizing potential

Scheme of exterior conjunctions of electrode and rectifier V-OPE-TM