SOP for Calibration Procedure of Process Instrument

1.0 OBJECTIVE:

To describe the Calibration Procedure of all the Process Instruments / equipment.

2.0 SCOPE :        

This Standard Operating Procedure (SOP) covers the Calibration procedure of the all Instruments /equipment in all departments of [company name].

Following Instruments / Equipment are calibrated by out side parties.

1. Pressure/Vacuum Gauge

2. Magnahaulic Gauge

3. Temperature Gauges / Dial Temp. Gauges / Glass Thermo meter.  (Mercury Type)

4. Temperature Controllers/ Temperature Indicators/ Chart Recorder.

5. Steel Rule

6. Voltmeter / Ampermeter.

7. pH Meter and Transmitter

8. RPM Indicators & Controllers.

9. Timer / Time Totalizer.

10. Humidity Indicator & Controller (Hygrometer)

11. Dial Indicator

12. Plain Plug Gauge

13. Vernier Caliper

14. Micrometer

15. Depth Vernier/ Depth Gauge

16. Conductivity meter

17. Measuring Devices

18. Stop watch

19. Weight box

20. Standard weights

21. Any other which added to existing.

3.0 RESPONSIBILITY:

Individual department Head:

To ensure for compliance of calibration as per schedule.

To coordinate with the outside party for Annual Maintenance Contract (AMC).

To receive the schedule for calibration and validation activity from QA department and give feedback and subsequent details.

Engineering department / other concern department personnel to coordinates for instruments calibration and perform in-house calibration as per schedule and to Coordinate with the outside party for AMC.

4.0 PROCEDURE:

4.1 All the instruments/ Equipment associated with the processing and testing of materials and products must be calibrated.

4.2 There shall be an SOP for calibration of each Instrument/Equipment that needs periodic in-house calibration.

4.3 QA personnel will prepare the schedule of monthly calibration and validation activity by taking printout from Validation Master Plan (VMP) in the end of the running month for the next coming month, and same shall be handed over to Engineering Head/Designee or other concern department personnel (as per the need).

4.4 The Engineering Head/other concern department personnel shall give feedback by giving the same schedule with the actual dates on which the calibration & validation activity to be performed in the 1st week of the next month.

4.5 QA personnel shall verify it and file the same for future reference.

4.6 The calibration data shall be entered in the calibration record. The calibration record shall contain details of calibration standards like Name, Control No. / Ref. No., Calibrated on, Next calibration due on etc. The calibration certificate shall be independently verified by second person.

4.7 During calibration, tag the Instrument/Equipment with “Under Calibration” label duly filled details.

4.8 Any Instrument/Equipment “Under Calibration” or due for its calibration shall not be used under any circumstances.

4.9 If the Instrument/Equipment passes the calibration test, put status label with duly filled details.

4.10 If the Instrument/Equipment fails in calibration test, put label with duly filled details and write “CF”  to indicate Calibration Failed.

4.11 When regular gauges or equipment / instruments are send outside the plant for calibration there shall be alternate arrangement adopted through filling necessary entries along with prior approval from Head QA.

4.12 Followings things are to be ensured before doing calibration with in the plant:

4.12.1 Ensure that the Master Instrument is calibrated (if any).

4.12.2 Ensure that the calibration certificate of Master Instrument is available or is traceable and confirm due date of next calibration.

4.12.3  In case the Instrument/Equipment fails in the calibration, failure shall be investigated by concerned Engineering personnel, respective department personnel along with QA personnel through incident report as per SOP for “Handling of Deviation and Incidents”. The reason for failure and the effect of failure on quality of product since last calibration shall be covered during investigation. The Deviation / Incident report shall be generated by the concern personnel. A copy of Deviation / Incident report shall be filed in the respective calibration file maintained in the QA department.

4.12.4  In case any Instrument / equipment is not possible to calibrate due to damage or if found to be out of Calibration range it shall be replaced with new calibrated one.

4.12.5  The Engineering department personnel / respective department personnel shall make necessary records (if required) of any such repairs or replacement in logbook remark column.

4.12.6  The replacement of any Instrument/Equipment shall be done through Change Control Form (CCF) by Engineering department personnel/ respective

department personnel. The defective Instrument/Equipment shall be disposed.

4.12.7  Put the label for calibration status with date of done on & due date for next calibration & with Calibrated by sign.

4.12.8  The instruments which cannot be calibrated in house/ or at site sent that instrument to approved vendor for calibration purpose. After completion of the calibration receive the instruments and check the physical condition of instrument, check the calibration certificate and tags. If both are OK than hand over instruments with tags to concern department for regular usage by locating it in its respective position, and original certificates to be handed over to QA department.

4.12.9  Unless and otherwise mentioned in individual sop for calibration, frequency of all Pressure Gauge, Vacuum Gauges Magnahaulic Gauge, manometer, Temperature Gauge, Dial Temperature Gauge, Glass Thermo meter, Temperature Controllers, Temperature Indicators, Steel Rule, Voltmeter, Ampermeter, pH meter, RPM meter, Tachometer, Timer, Time totalizer, Conductivity meter etc. follow frequency Once in Six Month. ±15 days

4.12.10 Unless and otherwise mentioned in individual sop for calibration of instruments like Vibrometer, Anemometer, DB meter, Lux meter, etc are to be calibrated by yearly once by the agencies like ERTL (Electronics Regional Test Laboratory) or National Standard (NSIT) once in a year±15 days as per calibration procedures specified in this sop.

4.12.11 The instrument / Equipment which are not to be calibrated in-house / by

contract party shall be calibrated by approved agencies such as ERTL / NSIT.

4.12.12 The frequency for calibration of all type of weighing balances shall be done as per their procedures ie. once in a six months ±15 days.

5.0 ANNEXURE:

Annexure – I Calibration procedure for pressure / vacuum gauge

Annexure -II Calibration procedure for Magnahaulic gauge/ Manometer

Annexure -III Calibration procedure for Temperature gauge / Dial Temperature / Glass Thermometer (Mercury Type)

Annexure -IV Calibration procedure for Temperature controllers / Temperature Indicators / Chart recorder.

Annexure -V Calibration procedure for Steel Rule

Annexure -VI Calibration procedure for Voltmeter / Ampere meter

Annexure -VII Calibration procedure for pH meter and Transmitter

Annexure -VIII Calibration procedure of RPM indicators and Controllers

Annexure -IX Calibration procedure of RPM of Equipment / Instruments

Annexure -X Calibration procedure of Timer / Timer Totalize

Annexure -XI Calibration procedure of Humidity Indicators and Controllers

Annexure -XII Calibration procedure Dial Indicators

Annexure -XIII Calibration procedure of Plain Plug Gauge

Annexure -XIV Calibration procedure of Vernier Caliper

Annexure -XV Calibration procedure of Micrometer

Annexure -XVI Calibration procedure of Depth Vernier / Depth gauge

Annexure -XVII Calibration procedure of Conductivity Meter

Annexure -XVIII Calibration procedure of Balance

Annexure -XIX Weighing Balance Calibration Record 

Annexure – I Calibration Procedure for Pressure/Vacuum Gauge.

Equipment used: Digital Pressure/Vacuum Pump (Comparator OR Dead weight tester) fitted with Standard gauge (IDEMI approved Gauge). 

1. Remove (Unplug) the PG/VG (To be calibrated) from the M/c.
2. Insure the Gauge is properly cleaned.
3. Remove air from Dead weight tester by moving screw piston to allow hydraulic oil to come out by loosening the gauge or vent hole.
4. After ensuring that no air bubble is present fix the gauge firmly and close the vent valve.
5. After removing of PG/VG, the end connection of PG/VG is connected to the pneumatic fitting of Digital Pressure/Vacuum Pump.
6. After connecting of this, apply the pressure/vacuum by Digital of pump cylinder.
7. By giving pressure/vacuum, check the variation of pressure/vacuum of PG/VG with the compare the variation of pressure/vacuum of the Master (Standard) gauge.
8. Take the approx. 5 readings at different magnitudes of pressure/vacuum.
9. Note down the both readings of PG/VG & Master gauge.
10. Compare the readings of PG/VG to the readings of the Master gauge.
11.  After comparing, if the readings of the PG/VG are within the accuracy limit. The PG/VG  is calibrated.
12.  Disconnect the pneumatic fittings from Digital Pressure/Vacuum pump & attach old fittings of that respective Machine/Unit.
13.  Put the label with date of Done on & due on for next calibration & Calibrated by sign. 

Annexure – II Calibration Procedure for Magnahaulic Gauge/Manometer.

Equipment used:  Digital Pressure/Vacuum Pump fitted with Standard gauge     ( IDEMI approved Gauge). 

1. Remove air from Test pump
2. After ensuring that no air bubble is present fix the gauge in Vertical position
3. on compactor tester machine and fix IDEMI approved gauge (standard  gauge) at the other end. And close the vent valve
4. If there is any deviation set ZERO on both gauges, when pressure is not
5. applied
6. Increase the pressure up to maximum reading with the help of compactor.
7. Check the pressure of under test gauge if it is not showing the Proper
8. reading adjust the span accordingly.
9. Check the lowest reading, if it is not showing the proper reading then set it
10. accordingly.
11. This procedure is to be done till equipment shows both lowest and highest reading.
12. Take readings for middle ranges and compare it with standard gauge.
13. Put the label with date of Done on & due on for next calibration & Calibrated by sign.

Annexure – III Calibration procedure of Temperature Gauges / Dial Temp. Gauges / Glass Thermo meter. (Mercury Type)

Equipment used: Oil / water Temp. Bath. Range: 0 To 300 deg. C

1.  Dial Temp. Gauge to be calibrated kept in calibration hole / temp. bath & Master temp. Instrument sensor kept in other temp. hole / bath.

2. Set desired temp. On temp. Controller & compare the dial temp. Gauge value with Master Temp. Instrument.

3. The calibration point should correspond to regularly spaced for temp. range.
4. Take the approx. 5 readings at different magnitudes of temp.
5. Note down the both readings of temp. gauge & Master Temp. Instrument
6. Compare the readings of temp. Gauge & Master temp. Instrument.
7. After comparing, if the readings of the temp. Gauges are within the accuracy limit. The temp. Gauge is calibrated

8. Put the label with date of Done on & due on for next calibration & Calibrated by sign. 

Annexure – IV Calibration procedure of Temperature Controllers/ Temperature Indicators/ Chart Recorder.

Equipment used: Standard RTD Simulator.

1. Remove the signal connection of RTD sensor and connect it to standard             Simulator.
2. Set the instrument to zero with the help of simulator.
3. Set the instrument span to highest and lowest operating temperature with  the help of simulator.
4. Check the reading for both at higher and lower level and if required set Zero and Span adjustment pots.
5. Apply an input signal equal to the high range value of the instrument through the simulator.
6. Apply 0%, 25%, 50%, 75% & 100% input on the simulator to the instrument under calibration.  
7. Note down reading shown by instrument.
8. After comparing, if the readings of the Temperature Controllers/ Temperature Indicators/ Chart Recorder are within the accuracy limit. The Instrument  is calibrated
9. Put the label with date of Done on & due on for next calibration & Calibrated by sign.  

Annexure – V Calibration procedure of Steel Rule.

Equipment used:  Standard Slip Gauge./ Digital Vernier Caliper

1. Check the Condition of Steel Rule.
2. Placed standard slip gauges with desired reading in accessories Set-holding jaw.
3. Holding this jaw on Steel Rule / Measuring scale; Use magnifying glass for Proper view on scale as well as on measuring jaw.
4. If Measuring jaw marking is between two scale division of Scale / Measuring tape than adjust the slip Gauges in measuring jaw so that scale reading can read properly.
5. The measurement shall be carried out according to the relevant standard of the Measuring Instrument to be calibration & the reference slip Gauges / Digital Vernier Caliper.
6. Note down difference between two readings.
7. Put the label with date of Done on & due on for next calibration & Calibrated by sign.

Annexure – VI Calibration procedure of Voltmeter / Ampere meter.

Equipment used: 1) Standard Multimeter. 2) Voltage Source.          

1. Connect the standard Voltmeter / Ampere meter & Unit Under Test to Voltage source, source should be given as per type of Voltmeter.
2. Set the Voltage source reading from lower to higher side of Voltmeter/ Ampere meter Range. Connect the standard voltmeter & Unit Under Test to Voltage source,
3. Note down difference between two readings.
4. Put the label with date of Done on & due on for next calibration & Calibrated by sign. 

Annexure – VII Calibration Procedure of pH Meter and Transmitter

1. Ensure that instrument is properly cleaned.
2. Before the electrode is dipped in a buffer solution, the electrode has to be cleaned with distilled water.  The electrode should then wiped with tissue paper.  Wherever applicable, the meter should be put in ‘STANDBY’ mode before wiping and should be brought back into the normal mode after wiping the electrode.
3. Dip the electrode in a standard buffer solution of pH = 7.00.
4. If instrument does not show 7.0 pH (± 0.1 pH) then adjust the ‘ASSYMETRY’ or ‘OFFSET’ pot till it shows 7.0 pH (± 0.1 pH). If necessary refer the user’s manual.  In case of pH transmitters the output should be 50% of span (Normally 12.0mA (± 0.16mA)   (for a 4 – 20mA output transmitter). If required refer the user’s manual for adjustment.
5. After the 7.0 pH adjustment done, dip the electrode in a standard buffer solution of pH 4.0 following the actions given in step ‘2’
6. Repeat steps 4.7.3 to ‘6’ till no further adjustment is necessary following the actions given in step  ‘2’.
7. Dip the electrode in a standard buffer solution of 9.2 pH following the actions given in step ‘2’.
8. If instrument does not show 9.2 pH (± 0.2 pH) then repeat steps ‘3’ to ‘8’.  In case of pH   transmitters the output should be 72% of span (Normally 15.52mA (± 0.32 mA) (for a 4 – 20mA output transmitter). If required refer the user’s manual.
9. Note down the readings.
10. Put the label with date of done on & due on for next calibration & Calibrated by sign.

Annexure – VIII Calibration procedure of RPM Indicators & Controllers.

Equipment used: Standard TECO Meter /Simulator

1. Ensure that instrument is properly cleaned.
2. Connect and Compare with suitable certified simulator to the signal input of the instrument.
3. Note down the low and high range of instrument.
4. Through RPM Controller (Test instrument), set suitable set point i.e. 25% RPM of the range. Now wait for settle set value of RPM.
5. Note down the reading shown by instrument (Test & master instruments).
6. If there is any difference between the master instrument reading and the reading of the Test instrument, then ‘ZERO’ adjustment has to be done.
7. Through RPM Controller (Test instrument), set suitable set point i.e. 85% RPM of the range. Now wait for settle set value of RPM. Note down reading shown by instrument.
8. Through RPM Controller (Test instrument) set 25%,  50% &  85% RPM of the range. Now wait for settle set value of RPM. Now note down the readings
9. Put the label with date of done on & due on for next calibration & Calibrated by sign.

Annexure – IX Calibration procedure of RPM of Equipment /Instrument

Equipment used: TECO Meter 

1.  Switch ON the equipment of which RPM to be checked.
2. Touch the tip of TECO meter to the rotating surface area of the equipment.
3. Check the reading shown by RPM meter with TECO meter
4. Take at least 5 to 6 readings and note down the same.
5. Note down the readings.
6. Put the label with date of done on & due on for next calibration & Calibrated by sign. 

Annexure – X Calibration procedure of Timer / Time Totalize.

Equipment used: Standard Stop Watch / Timer

1. Ensure that instrument is properly cleaned.
2. Connect and Compare with suitable certified timer/ Stop Watch to the signal input of the instrument.
3. Note down the low and high range of instrument.
4. Through Digital Timer (Master instrument), set time in sec. i.e. 25% of the range and start both timer at once.
5. Note down the reading shown by instrument (Test & Master instruments).
6. Through Digital Timer (Master instrument) set 25%, 50% , 75% & 85% Now note down the readings.
7. Put the label with date of done on & due on for next calibration & Calibrated by sign. 

Annexure – XI Calibration Procedure of Humidity Indicator & Controller.

Equipment used: Humidity Controller Chamber

1. Ensure that instrument is properly cleaned.
2. Connect and Compare with suitable certified Humidity Controller Chamber to the signal input of the instrument.
3. Note down the low and high range of instrument.
4. Through Humidity Controller Chamber (Master instrument), set suitable set point i.e. 25% Humidity of the range. Now wait for settle set value of Humidity.
5. Note down the reading shown by instrument (Test & Master instruments).
6. If there is any difference between the master instrument reading and the reading of the Test instrument, then ‘ZERO’ adjustment has to be done. (Refer the Manufacturer’s manual.).
7. Through Humidity Controller (Master instrument), set suitable set point i.e. 85% Humidity of the range. Now wait for settle set value of Humidity.
8. Through Humidity Controller (Master instrument) set 25%, 50% & 75% Humidity of the range. Now wait for settle set value of Humidity. Now note down the readings.
9. Put the label with date of done on & due on for next calibration & Calibrated by sign.  

Annexure – XII Calibration Procedure of Dial Indicator. 

Equipment used: Gauge Block

1. Check the Condition of Dial Indicator.
2. Check the Condition of Scale & Numbers.
3. Soak the Instrument in 20ºC at least for 1 hour.
4. Mount the Dial Indicator on Surface Plate and set zero on Dial.
5. Place the Gauge Block between Dial Indicator and Surface Plate according to least count.
6. Take readings according to the range.
7. Put the label with date of done on & due on for next calibration & Calibrated by sign.        

Annexure – XIII Calibration Procedure of Plain Plug Gauge.

Equipment used: Dial Indicator, Surface Plate

1. Check the Condition of Plug Gauge.
2. Soak the Gauge in 20ºC at least for 1 hour.
3. Mount the Dial Indicator on Surface Plate and set zero on Dial.
4. Place the Gauge Block between Dial Indicator and Surface Plate according to Size of Plug Gauge.
5. Take readings according to the range.
6. Put the label with date of done on & due on for next calibration & Calibrated by sign.  

Annexure – XIV Calibration Procedure of Vernier Caliper

Equipment used: Dial Indicator, Surface Plate, slip gauge.

1. Ensure that the measuring faces, Vernier Scale, Main Scale, Depth Measuring Blade are free from damages and check the free movement of slider.

2. Check the clarity of scale and numbers.
3. Check the zero error.
4. Soak the instrument along with master equipment in 20c at least for 1 hour.
5. Check the parallelism of the faces for external measuring by inserting gauge  block between the different points of the jaws and at different measured length.
6. Check the parallelism of internal measuring faces by using slip gauge &  vernier caliper at different points on measuring faces of the jaws.
7. Check the inherent error in external jaws of Vernier Caliper with gauge block      combination  of known size to cover a number of paints both over the range      of instrument and that of instrument in steps.

8. Check inherent error in internal measuring jaws of vernier caliper by placing      the measuring faces of the gauge blocks between the measuring jaws of slip  gauge and Vernier Caliper and check the inside measuring faces of the caliper to check the error in measurement over range of instrument in steps as indicated below.

9.  Dimensions to be measured should be aligned parallel to the beam of       Caliper and stress on the Caliper should be avoided.

10. Check the Zero error in depth measurement blade by holding Vernier Caliper       in Vertical position on gauge block surface which is kept over the surface       plate and then opening jaws of Vernier Caliper in vertical  position.

11. Check the zero error in step measuring face by keeping step measuring face  of sliding jaws on gauge block which is kept over surface plate.
12. Vernier Calipers – The following table shall give the required steps of measurement to be taken in order to cover the full range of equipment :25.00, 50.00, 75.00,100.00,175.00
13. Take readings according to the range.
14. Put the label with date of done on & due on for next calibration & Calibrated by sign.   

Annexure – XV Calibration Procedure of Micrometer.

Equipment used:Slips gauges

    1.Ensure that the measuring faces are free from any damage, rust.

    2.Wipe faces clean , Checks for smoothness in traverse , lubricate with light oil if required.

    3. Check the zero error , if any , by directly touching measuring faces or by using slips gauges as required in case of bigger ranges and adjust zero error if necessary.

    4. Soak the instrument along with master equipment in 20c atleast for 1 hour.

5. Check the parallelism of measuring faces by using a slip gauge  at different points in measuring faces , difference between  maximum and minimum reading gives parallelism error.
6. Check the deviation  of traverse of micrometer screen , taken the readings in steps over full range with the series of slip Gauges.
7. Micrometer – The following are the required steps of under measuring to be taken in order to cover the full range of equipment.2.500,  5.100, 7.700, 10.300, 12.900, 15.000, 17.600, 20.200, 22.800,  25.000
8. Micrometer of range above 25mm  a slip Gauge of lower range size shall be      used in conjunction  with combination , of  Slip Gauge as mentioned  above      e. g. for Micrometer 25 -50mm range Slip Gauge of 25.00mm shall be used  in  conjunction  with slips mentioned above i.e. 2.5 , 5.1 , 7.7 ,……etc.

9. Micrometer with master , master shall be checked individually with Slip  Gauge Combination of nominal size and by using dial indicator of  L.C. 0.001 mm.
10. Note the readings according to range.
11. Put the label with date of done on & due on for next calibration & Calibrated by sign.   

Annexure – XVI Calibration Procedure of Depth Vernier/ Depth Gauge

Equipment used:Slips gauges 

1. Ensure that the measuring faces, Depth Vernier, main Scale free from damages and check the free   movement of slider.
2. Check the clarity of scale and numbers.
3. Check the zero error.
4. Soak the instrument along with master equipment in 20c at least for 1 hour.
5. Check the parallelism of the faces
6. Check the Zero error in scale by holding Depth Vernier  in Vertical position on gauge block surface which is kept over the surface plate and then opening jaws of Depth Vernier  in vertical  position.
7. Place the measuring faces of the slip gauge blocks  between the measuring jaws and surface plate and check measuring faces of the caliper for error in measurement over full range of instrument in steps.
8. Dimensions to be measured should be aligned parallel to the beam of Caliper and stress on the Caliper should be avoided.
9. Depth Vernier  – The following table shall give the required steps of measurement to be taken in order to cover the full range of equipment :       25.00, 50.00, 75.00, 100.00,150.00

10. Note the readings according to range.
11. Put the label with date of done on & due on for next calibration & Calibrated by sign. 

Annexure – XVII Calibration procedure of Conductivity meter.

1. Calibration method of conductivity meter is depends upon type of sensor used for Conductivity (Cell Constant 1, 0.1, 0.01). We are herewith giving cell constant chart with respect to ohms.

2. As per given chart connect input to Conductivity Meter & check the output (display reading) of Conductivity Meter.
3. If found deviation, then correct it by using setting pot if available.
4. The point should correspond to regularly spaced value of the Conductivity Range
5. Take at least 5 to 6 readings such that we cover the full range of the instrument.
6. Note down the readings from Standard v/s under test Conductivity Meter.
7. Put the label with date of done on & due on for next calibration & Calibrated by sign.

Annexure – XVIII Calibration procedure of Balance

1. All the balances to be used for the testing and process or inspection purpose shall be calibrated.
2. Daily calibration shall be done by using minimum two weights preferably minimum and maximum weight / operating range shall be calibrated.
3. Display the operating range of usage on balance for clear identification. Follow the instruction given in respective SOP of the balance.
4. Periodical calibration of the balances shall be done by using external weights total range shall be covered. Follow the instruction given in respective SOP of the balance.
5. Daily and periodical calibration details of the balance shall be recorded in the calibration record refer annexure XIX.

Annexure – XIX Weighing Balance Calibration Record

Department:

Weighing Balance Calibration Record

Id. No:           

Location:

Operating Range:  

Least Count:

ID No. Of the Weight Box Calibrated On         

Next Calibrated Due On

Frequency: On first working day of the month.

Frequency: Daily or before use.