Real Life Examples of how Calibration helps Companies

The National Center for Quality Calibration is a part of Punyam Management Services Pvt. Ltd. (Leading ISO Consultancy Firm) during our ISO 9001 implementation we had gone across few experiences of our clients which are listed below;

Case Study –1 (Fire caused major damages to property and Human)

Chemical Process Plant

Critical reactions were carried out in the pressure vessel – steam jacketed. Process was going on the reaction was exothermic in nature.

Controlling – Monitoring Points

• Pressure Gauge – Steam pressure monitoring – inside jacket
• Temperature Controller – Temperature monitoring inside the vessel
• Pressure Gauge – Vessel inside pressure monitoring

Status of Instruments

• Non calibrated
• In operation since 5 years

Incidence

Due to increase in steam pressure and exothermic reaction, pressure and temperature inside the vessel increased more than safe working capacity of pressure vessel. Pressure goes to above 10 Kg/cm2 and temperature goes to above 700°C (above flesh point of 690°C). But actually on monitor it Temperature Controller (Shows only 620°C) was not calibrated.

Reason
Indication inside the vessel reaction and temperature, were showing as within the process control limit.

Results - Vessel Blast

Damages to

• Major damages to plant, collapsed structure huge loss in terms of money.
• 2 operators working near by affected seriously and got permanent disability.

Could be controlled

• If instruments were calibrated periodically,
• Knowledge of calibration amongst employees

Conclusion - Rs. 1000/- per annum can serve loss of lacs of rupees and happy human life.

Case Study –2 (Saves Product Quality)

CNC Machine for preparation of mould

Very costly dies of plastic processing machines were produced in CNC machine in various sequence of operation.

Controlling – Monitoring Points 

Programme is entered in PLC through IOP as per the relevant design / drawings submitted also same can be monitored through IOP.

Status of Instruments Calibration

• PLC, IOP not validated / calibrated with respected to actual travel / traverse / feed / axial / radial play.
• In operation since 10 years

Incidence

Due to increased radial and axial play about 0.5 mm, the critical dimensions on the die could not controlled. Two nearest holes comes near each other due to higher play and crossed each other by 0.1 mm.

Reason
Indication on IOP guided by PLC was showing dimensional movement of machine as per programme.

Results - Loss of quality in dies. Die rejected due to crossing of holes with each other.

Damages to

• End product quality   
• Product rejection rate high
• Loss of image in the eyes of customer   

Could be controlled

• By periodic calibration of traverse / feed / play
• Knowledge and requirements of calibration amongst employee, even through highly accurate machines

Conclusion - Loss of product quality worth in lacs of rupees.

Case Study –3 (Higher Consumption in Energy)

Material Transfer Pump With Motor

Material transfer pump with motor was engaged in transferring of materials from reaction vessel to holding vessel and it tooks about 12 hours a day. Pump working daily 12 hours.

Controlling – Monitoring Points
Ampere Meter – Showing load taken by motor during pumping

Status of Instruments

• Non calibrated
• In service since 4 years

Incidence

Due to long working duration, pump was jammed and rotating with too much friction. Due to same the motor was working always in overload condition. However ampere shown on Ampere meter were indicating, that the motor is working in safe rating. However motor was taking 10 ampere overload than the specified current rating. The same caused higher energy consumption.

Reason - Indication in Ampere were showing safe current limit.

Results - Higher electricity bills. I.e. 125% of total required consumption of motor.

Damages to

• Company’s financial stability, increase in manufacturing cost of product.
• Could be controlled
• If Ampere meter was calibrated periodically
• Knowledge of calibration amongst employees

Conclusion - 25% higher energy consumption due to extra 10 ampere on specified rating.

Case Study –4 (Less Productivity)

Length of Material measure by Mtr/Min Meter
In textile process unit length of material measured by Mtr./Min Meter.

Controlling – Monitoring Points
Mtr./Min Meter – Showing length of material

Status of Instruments

• Non calibrated
• In service since 3 years

Incidence

Due to long working duration, Mtr/Min Meter was showing wrong reading. However Mtr/Min Meter was showing 100 meters instead of 110 meters.

Reason - Mtr/Min Meter was showing wrong reading.

Results - Less productivity. i.e. 10% more material consumption.

Damages to
Company’s financial stability, increase in manufacturing cost of product.

Could be controlled

• If Mtr/Min Meter was calibrated periodically
• Knowledge of calibration amongst employees

Conclusion

• 10% less productivity due to Mtr/Min Meter was showing 10% less reading
• The electronic  equipment in the actual humid / chemical work environment may show error over a period of life span (after 2 to 3 years). It is therefore advisable to check and calibrated once in a year.
• Actually calibrated equipment with more precise masters will save your lacs of rupees due to safety, save energy consumption, increase product quality
• Also prefer to carry out actual calibration of instrument from reputed calibration laboratory rather then taking report of calibration.

Calibration of test equipment
Calibration for pressure gauges

Selection of Instrument for Ensuring Reliability in Measurement

There are many types of instrument available in the market but in calibration process we should select the instrument by which our all requirement for the particular measurement can be fulfilled and the instrument is most convenient for that measurement. So for selection of instrument following point should be considered.

Range

In selection of instrument first point will be what should be the range of instrument. In dimension calibration instrument the maximum range of the process is considered, by which the maximum dimension will be measured and according to that the instrument range will be decided (i.e. For the selection of Vernier the maximum dimension of the job is 140 mm than the Vernier will be of 0 – 150 mm range). But in selection of bourdon tube type gauges (pressure gauges, temperature gauges) the instrument range should be 1.5 to 2 times more than the process range. Because in bourdon tube type gauges it gives most accurate results on middle ranges (i.e. If the process requirement is between 3 – 7 Kg/Cm2 than the pressure gauge of 10 Kg/Cm2 will be better). Because of the hystersis related mechanism in the bourdon tube, it gives the perfection in the results only at the 20 – 80 % range of pressure gauge. Means the gauge of 0 – 10 Kg/Cm2 can gives perfect results only at the 2 – 8 Kg/Cm2. Hence the selection of range becomes very crucial at this stage.

Least count

After selection of range the other main criteria is of least count. The instrument cost also depends on the instrument least count. Instrument least count should be sufficient four our requirement. So the best suitable least count is decided based on the tolerances of the process. Generally the instrument least count should be 2 to 3 times better than tolerance requirements of process. I.e. The calibration process tolerance is 0.05 mm than the instrument least measurement capability should be at least 0.02 mm or less.

Working Atmosphere and personnel skill

In the selection of instrument the atmosphere where it is to be used or by whom it is to be used, is also equally important. In the plant where dusty atmosphere and there may be chances of touch with oil, chemical fumes and vibration. The stability and accuracy of electronic instruments does not remain constant for long time. Hence better way is to use specially designed instruments or mechanism type instruments. I.e. In measurement of chemical pressure, diaphragm pressure gauges is most reliable with glycerin filled, which can gives stability to the gauge during vibration.

Identification of instruments for calibration

For any industry there is a big question regarding calibration is, which instruments should be calibrated. All the instruments in the process / plant need not to be calibrated only some identified instruments are needed to be calibration. For identification of instruments for calibration following points to be considered.

• The instruments affects in terms of process control parameter. Means the instruments used to control the process parameters like temperature controller, timer, go no-go gauges.
• Affects process in terms of life of equipment. In some pressure vessels liquid is feed or stored at some pressure if the pressure increases than the rated (designed) there may chances of explore of leakage so that monitoring instruments must be calibrated.
• Affects quality of product. The instruments used in quality control must be calibrated because they decide the quality of product. If they will not have quality then you will not have quality product.
• In-house templates, jigs, fixtures are must be calibrated. Jigs and fixtures are used in mass production so timely calibration of that instrument must be needed because any deviation beyond tolerance in that may case rejection in a big lot.
• Referred / identified in ISO documentation for process monitoring or measurement that instruments must be calibrated.

Hence the above points needs to be considered during the selection of instruments for better measurement and providing reliability in the measurement.

 Read More about
iso 17025 calibration laboratory

NCQC Received NABL Certificate for Year 2012-2014 with Expands in Scope

With increased emphasis on quality by the government in instruments calibration, testing and calibration laboratories have begun to seek ISO/IEC 17025 accreditation from the NABL(National Accreditation Board of Laboratory). Though accreditation raises competitive status of the calibration laboratory, National Center for Quality Calibration (NCQC) continuously improves with extends the instrumentation, knowledge and the NABL accreditation scope every two year in all the department mechanical, electro-technical and thermal calibration. In Feb 2012, NCQC has successfully completed NABL audit and receives NABL certificate which is valid from 11 April 2012 to 10 April 2014.

NCQC NABL Certificate - Mechanical, Electro-technical and Thermal

Through the past years NCQC, the leading NABL accredited calibration laboratory in India had follows all the requirements of NABL standard for instrument calibration in all the three department mechanical, electro-technical and thermal calibration. In year 2012, NCQC purchased the latest master instruments for expands the scope of calibration services. The team of highly experienced and qualified engineers has successfully completed NABL audit taken by Members of National Accreditation Board of Laboratory.

NCQC is recently extended and currently performing calibration in the field of Temperature, Dimensional, Pressure, Vacuum, Time, mass calibration, Electrical, Noise, Airflow, Lux & all Special Purpose Instruments in all ranges. NCQC calibration Laboratory's quality system is accredited to ISO/IEC 17025:2005 by NABL. We are  ISO/IEC 17025 (NABL) accreditation in the field of Mechanical, pressure and vacuum, force, mass, volume, thermal, electro - Technical as per latest ISO standard ISO/IEC 17025 (NABL Certificate No. C – 0146, C – 0499, C – 0502). To download our NABL certificate or our scope of certificate downloads it from company website http://www.calibrationlaboratory.in/

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National Center for Quality Calibration

902, 903, Samudra Annexe,

Near Hotel Klassic Gold, Girish Colddrink Char Rasta,

Off. C.G.Road

Ahmedabad – 380006

Gujarat

India.