HOW TO CALIBRATE ORP ANALYSER

This Procedure is intended to provide guidance and instructions for carrying out the maintenance of Oxidation-Reduction Potential ( ORP ) ANALYSER as per standard practices prescribed by OEM or General Industry best practices in safe manner while ensuring minimization of environmental impacts to the extent possible.

GENERAL INSTRUCTIONS FOR COMPLIANCE:

• Work permit as should be secured and instructions provided in the permit should be complied. Where instructions are not clear, clarification should be requested from the concerned Supervisior.

• Work should only be commenced after ensuring that proper work environment is created (Authorizations are secured, Isolations are confirmed, and required mobilization is done).

• Access to Emergency evacuation and other emergency services such as medical and Fire protection shall be readily available and contact details are readily available concerned supervisor as well as contactor.

• Access to drinking water, toilet and other essential infrastructure for both company and contract personnel should be ensured.

WORK INSTRUCTION PROCEDURE:

  DETAILS OF HAZARD INVOLVED

a. Electric Shock.

b. Fire.

c. Injury due to improper handling of Equipment.

4.3.2 SAFETY PRECAUTION REQUIRED

a. Ensure proper ventilation at the work place.

b. Ensure use of proper PPE’s

c. Keep the fire extinguishers (CO2 gas / DCP) ready within reachable limit for any exigency at the vicinity of work place.

d. Ensure proper Earthing.

e. Ensure proper illumination.

f. Ensure proper range of multi meter & test probe for different measurement.

g. Insulated general tools to be used.

h. Ensure good housekeeping of maintenance site.

i. Permit Type: Permit to Work Order.

j. Permit Approving Authority: Shift in-charge (Main Control Room).

T&P INCLUDING SPECIAL ONES

a. Multi meter

b. Standard buffer solution of known ORP

c. Insulated General tools.

d. Tissue paper.

SPARES & CONSUMABLES

a. Silica sealants

b. Teflon Tape

FREQUENCY OF MAINTENANCE

Every 3 month / In case of failures.

WORKING INSTRUCTION:

STANDARD MAINTENANCE PROCEDURE

a. Check the tightness of all cable terminations & tube fittings.

b. Ensure healthiness of transmitter & sensor.

c. Before switch off the power supply, ensure transmitter display should be proper.

d. Reading in transmitter display should match with PLC.

e. If transmitter showing error/bad reading, calibration of the transmitter should be done.

f. Isolate the sample line drain the sample.

g. Check the electrolyte solution level wither it is filled or not, if not; fill the same.

h. Remove the ORP sensor from sample chamber.

i. Clean the ORP sensor with D.M. water & dry it with tissue paper.

j. After cleaning, put the ORP analyzer sensor in sample chamber open isolation valve & take the sample in line.

STANDARD CALIBRATION PROCEDURE

a. Isolate the sample line drain the sample.

b. Remove the ORP sensor from sample chamber.

c. Clean the ORP sensor with D.M. water & dry it with tissue paper.

d. To eliminate temperature related errors, disable temperature compensation & calibrate using the ORP of standard solution at the measured temperature.

e. Place the sensor in standard buffer solution of known ORP.

f. Note down the reading before calibration.

g. If the deviation is not within limits, place the sensor in Buffer solution & adjust the analyzer reading to match the known ORP.

h. Repeat step and readjust readings of analyzer if required, till ORP analyzer readings are matching with the standard buffer solution values.

i. Adjustment of analyzer

j. Press “MENU” button.

k. Select “Calibrate” & press “ENTER”.

l. Select SENSOR 1 OR SENSOR 2 corresponding to ORP, Press ENTER.

m. Select ORP, Press ENTER.

n. Select “Buffer calibration”.

o. Select “Auto”.

p. Select “Start auto calibration”.

q. Place sensor in buffer & press ENTER.

r. Wait for 10 sec, when reading is stable, then input the value manually (which will be same as standard solution).

s. After calibration, put the ORP analyzer sensor in sample chamber open isolation valve & take the sample in line.

t. Fill the calibration sheet with all necessary details, i.e. - Test equipment used, calibrated by and etc.

CHECKS BEFORE RELEASE OF PERMIT

a. All T & P’s and manpower are removed.

b. Clean the maintenance area properly.

c. Normalize all isolation & Return PTW

HANDLING OF CONCESSIONS OR DEVIATIONS:

√ In the Event of Any Changes or Deviation from Procedure are required due to Urgent business requirements or system/Equipment approval should be obtained from Head O&M.

√ The report for the concerned task should clearly Captured the details of deviations and reason for the same.