Purpose

Indicator is intended for identification of insulating flanges and sleeves on pipelines with insulation resistance less than 10 Ohm for identification of the contacts between pipelines, cases, liners and other metal constructions.
Operating conditions

Indicator provides stable and reliable operation under the following climatic conditions:
- the upper value of ambient temperature +55 °C;
- the lower value of ambient temperature ?20 °C;

the upper value of relative humidity 90% at +30 °C and at lower values of temperature without moisture condensation.
Technical data

Parameter	Standard
1. Resistance of the external circuit between the contact blades connected with an object at which the indicator light “Closing” is switched on, Ohm	10 ± 2,5
2. Supply voltage, V	4,8...6
3. Resistance of the external circuit between the contact blades connected with an object at which the indicator light “Contact” is switched on, MOhm, not less	0,5
4. Maximum current of consumption in the mode of indication, mA	100
5. Maximum current of consumption in the off mode	0,05

The Indicator of insulating joints condition ISEIS corresponds to the technical specifications TU 3435-004-51996521-2005.
Principle of operation

The operation of the indicator is based on comparison of voltage drop on the insulating joint with standard voltage. The comparison is made at alternating current, that is why complex impedance on the insulating joint is taken into account. The indicator is switched on automatically when resistance between the contact parts is less than 0.5 MOhm or when the device is under voltage. The indicator is switched off 3-5 seconds later after switching off the contact parts. When the indicator is switched off current consumption is negligibly small in comparison with self-discharge current of supply elements.

Fig.1 - Construction