Purpose

Evaluation of corrosion hazard under the influence of stray currents considering polarity of potential ohmic drop between the construction and auxiliary electrode.

Measurement of potential shift of underground metal pipelines under the influence of alternating current.

Evaluation of ground corrosion hazard under laboratory conditions.

Measurement of polarization potential of underground metal pipelines.

Measurement of potential difference between the underground metal construction and reference electrode.

Determination of existing stray currents in the ground.
Features

Simultaneous displaying of polarizing and compound action protective potentials values
Operating conditions
Meter ensures reliable and stable operation in all climate regions under the following climatic conditions:
- the upper value of ambient temperature + 55°С;
- the lower value of ambient temperature - 10°С;
- the upper value of relative humidity 90% at 25°С.
Technical data

Parameter's name	Standard
1. Current consumption from the battery, not more than, mA	40
2. Supply voltage from the battery, V	4,3...6
3. Setting time of operating conditions, not more than, min	1
4. Continuous running duration of battery-operated device, hours	48
5. Withstands at measurement inputs voltage overload during one minute, V	9
6. Measurement range of polarizing potential, V	-4,997...+4,997
7. Measurement range of compound action potential, V	-4,997...+4,997
8. Weight of the device including the battery, not more than, g	400
9. Overall dimensions, not more than, mm	161х85х45

Construction

Instrument case is made of impactproof material. Control and indication members are protected by a flap lid. Principle of operation
Structural electric scheme of potential meter ORION IP-01

Fig.1 Structural electric scheme of potential meter ORION IP-01

Voltage converter is intended to convert voltage from the battery into bipolar voltage of ?7V required for operation of the device.

Non-polarizable copper sulphate reference electrode with potential sensor is not included as a component of the device. While making measurements, one must allow for an electrode error.

Charge stored in capacitor C1 is equal to the construction’s polarizing potential value. This charge enters polarizing potential input buffer intended to provide high input resistance while measuring polarizing potential to exclude shunting effect on the input channel of measuring circuit.

Polarizing potential detection unit provides for analog integration and division of potential value by 2.

Potential from the pipeline relative to non-polarizable reference electrode enters compound action potential input buffer intended to exclude shunting effect on the input channel.

Compound action potential detection unit provides for analog integration and division of potential value by 2.

Standardized-value voltage, proportional to input polarizing and compound action potentials, enters inputs of negative voltage conversion unit. This unit forms voltage of positive polarity at the input of analog-to-digital converter (ADC) at any polarity of input potentials and appliance of control signal of polarity mark to the input of central processor.

Analog-to-digital converter converts input voltage into pulse sequence.

Central processor unit controls operation of all units.

Display unit with the integrated controller provides for displaying on LCD value and polarity mark of input potentials, delay duration and battery voltage values.

Button S1 is used to select delay duration value.

Electronic switch consists of polarity key (PK) and charge key (CK). The switch is used to detect construction’s protective potential with the exclusion of resistive component by means of charge transfer from the pipeline relative to non-polarizable reference electrode through polarity key onto potential sensor with the consequent charge transfer through charge key onto the condenser C1.

Simplified scheme of electronic switch and temporary diagrams of key operation are shown in Fig. 2 and 3. When PK is closed the potential sensor is polarized by current to the chain: ground – potential sensor – pipeline. When PK is closed polarized potential from the potential sensor is accumulated on the condenser C1. When PK is disengaged current does not go through the potential sensor and there is no ohmic resistive component on it. Button S1 is used to set one of four values of charge impulse positive edge time delay relative to positive polarization impulse decrease in the range of 0.2-0.4-0.8-1.6 ms that ensures evaluation the degree of polarization potential decrease. .

Рисунок 2 - Упрощенная схема электронного коммутатора
Рисунок 3 - Временные диаграммы управления ключами заряда и поляризации электронного коммутатора