The document discusses calibration, including defining calibration as checking the accuracy of measuring instruments against a standard. It describes various calibration laboratories and standards in India such as NPL, ERTL, and ETDC. It explains the importance, purpose, and types of calibration, as well as requirements for calibration management systems and common instrument calibrations.

1. Poornima Institute of Engineering & Technology
A presentation on

2. Electronics Test & Development Center

3. NPL India NPL, UK NIST, USA
ERTL-E ERTL-W ERTL-N ERTL-S OTHER
ETDC
States
OTHER
LAB
ETDC
States
ETDC
States
ETDC
States
Calibration labs
NPL – National Physical Laboratory.
ERTL – Electronics Regional Test Laboratory.
ETDC – Electronics Test and Development Center

4. About NCQC - Calibration Laboratory in India
National Centre for Quality Calibration Laboratory
The NCQC was founded in 1998 for instrument calibration
laboratory. Since then, It has steadily grown by adding many new
facilities, capabilities including primary and secondary
instrumentation to become leading NABL calibration laboratory
in India. They provide calibration services to customers in either
their own environmentally controlled multi-laboratory facility or
on-site at their location. They are NABL accredited Calibration Lab
is having wide scope of thermal, mechanical and electro-technical
instrument calibration. It has branches in Gandhidham,
Ankleshwar, Bhavnagar, Rajkot and Vapi.

5. TYPES OF MEASUREMENT STANDARDS

6. Traceability
Traceable to a national standards.
In India it is with National Physical
Laboratories, New Delhi.

7. About ETDC
Government of India, provides quality assurance services in the
area of Electronics and IT through countrywide network
laboratories and centers. The service includes Testing,
Calibration, IT & e-governance, Training & Certification to
public and private organizations.

8. What is Calibration?
Calibration is the activity of checking, by
comparison with a standard, the accuracy of
a measuring instrument of any type. It may
also include adjustment of the instrument to
bring it into alignment with the standard.

9. Why is Calibration Necessary?
It is impossible to make perfect hardware that would not need any
form of error correction. Even making the hardware good enough
to eliminate the need for error correction for most devices would
be extremely expensive.
The best balance is to make the hardware as good as practically
possible, balancing performance and cost. Calibration is then a
very useful tool to improve measurement accuracy.

10. Importance of Calibration
Calibration of a measuring equipment or working standard enables
the user to take note of the deviations and errors from the nominal
values so that corrections can be made to minimize the errors
during measurement.
A well-calibrated instrument provides the confidence to the user as
well as the consumer that the service or the product meets the
required specifications and ensures the acceptance in international
market.

11. Purpose of Calibration
Calibration refers to the act of evaluating and adjusting the
precision and accuracy of measurement equipment. Instrument
calibration is intended to eliminate or reduce bias in an
instrument's readings over a range for all continuous values.
 Precision is the degree to which repeated measurements under
unchanged conditions show the same result.
 Accuracy is the degree of closeness of measurements of a
quantity to its actual true value.

12. Types of Calibration
Calibration is basically of three types:
i. Electro-technical Calibration: It consist calibration
of electronic devices like resister, capacitor etc.
ii. Non Electrical Calibration: It consist calibration of
mass, pressure etc.
iii. On Site Calibration: It consist calibration of any
other type of quantity which contain both quantities.

13. Where to Calibrate?
 Calibration is performed in the I/II/III party
laboratory under controlled environment.
(The environment need only to be controlled to
the extent required.)
 Accredited Calibration Laboratory
 Manufacturer’s / Supplier’s Laboratory
 ensuring valid traceability

14. Location – Permanent/On-site
Equipment
Calibration laboratory - basic requirements
 Temperature
 Humidity
 Air flow
 Filtration
 Electromagnetic Screening
 Noise Level
 Vibration
 EMI/EMC
 Cleanliness
 Lighting
 Power supply
 Accessibility
 Receiving & Calibration area
Reference standards
Transfer Standards
Working standards
Connecting leads
adaptors/accessories
Subsidiary equipment
Computers & automation
software
Training
Authority
Responsibility
Technical
Competence
Documents
Records
Calibration
Environment
Staff
Management

15. Requirements of Calibration Management System
Each instrument requires:
 Unique identification
 A recorded history and current calibration status
 Use appropriate for the function of the instrument
Calibration procedures require
 Approved procedures for calibration
 Schedule for calibration
 Process range limits
Calibration standards and test equipment
 Must be more accurate than the required accuracy of the instrument
 Traceable back to national or international standards
Personnel
 Proof of appropriate training
 Perform within an established change management process

16. Common measurements
• Inspection, Measurement, and Test Equipment
(IM&TE)
• To calibrate any equipment, it is necessary to
generate a known amount of the variable to be
measured and apply it to the unit under test.
• Variable can be generated by using known generator
(i.e. gage block) or unknown generator (in the case it
must be measured simultaneously with calibrated
device).
• Where IM&TE is also a generator then the output
must be known.

17. COMMON MEASUREMENTS (cont’d)
• Laboratory Measurement of Temperature:
– Liquid-in-glass thermometers must be immersed in
the calibration bath to a predefined depth.
– Resistance-Temperature-Devices work on the basis
of temperature versus resistance characteristics.
– Optical Pyrometer is used to measure temperatures
above 200C by measuring the color of the object
from the distance.

18. Equipment used for temperature calibration
Equipments like RTD, Oil temperature bath and highly
accurate glass thermometers are used for temperature
calibration.

19. COMMON MEASUREMENTS (cont’d)
• Laboratory Measurement of Humidity:
– Humidity is best measured using a chilled mirror
hydrometer.
– Psychomotor measures humidity by comparing
the temperature near a dry bulb with that of a
wet bulb (the lower the humidity the greater the
cooling)

20. COMMON MEASUREMENTS (cont’d)
• Laboratory Measurement of Pressure:
– The most accurate way to measure pressure is
to generate it (weight divided by the area).
– Low pressures can be measured using
manometer (column of liquid responds to
positive and negative pressures).
– The Bourdon gage measures pressure by
mechanical means of elasticity (elastic element
used).

21. Measurement of pressure (cont’d)
– The Quartz Bourdon gage measures
pressure by means of electronic transducer.

22. COMMON MEASUREMENTS (cont’d)
• Laboratory Measurement of Torque:
– Torque is difficult to generate and measure.
– Greatest uncertainty, when it comes to
measuring torque, is the distance from the
center of the mass to the center of the rotating
lever arm

23. COMMON MEASUREMENTS (cont’d)
• Laboratory Measurement of Force:
– Force is generate by hanging calibrated
weights on the unit under test (requires
correction to local gravity).

24. COMMON MEASUREMENTS (cont’d)
• Laboratory Measurement of Mass:
– Masses are calibrated by comparison to
known and traceable reference standards.
– Gravity correction required?????
• No, if the materials of the standard are the
same as of the unit under test.
• Yes, where there is difference in materials.

25. Equipments used for mass calibration

26. COMMON MEASUREMENTS (cont’d)
• Laboratory Measurement of Electrical
Quantity:
– Electronic Calibrators, Capacitors and Inductors,
Digital Multimeters, Null Indicators, Bridges and
Transfer Standards.
– Number of digits on the display does NOT mean
that the same level of accuracy has been
achieved.
– In case where DC is used, special attention
should be paid to high and low voltage (potential
results distortion)

27. Measurement of electric quantity (cont’d)
Electric equipments like Multimeter , clamp
meter, voltmeter are calibrated.

28. COMMON MEASUREMENTS (cont’d)
• Laboratory Measurement of Time and Frequency:
– GPS (Global Positioning System) signal is
considered traceable to national standards and
has output of about 10MHz (at full capacity).

29. Standard Equipments

30. Calibration Report
Calibration Report
A calibration report usually provides a set of
results that show the performance of the instrument
being calibrated in comparison to a reference
instrument or standard. Measurements are recorded
for each function, range and points tested, and the
uncertainty of each measurement is reported.

31. Calibration Certificates
Calibration Certificate
A calibration certificate usually states the
compliance of an instrument with the
manufacturer's specification. Measurements made
by the instrument being calibrated are compared to
the manufacturer's specification. If the instrument is
within specification, a statement that the instrument
meets the manufacturer's specification at the points
tested is made in the conformance certificate.

32. Futures of Calibration System at NCQC
 Identifies instruments that can be calibrated
 Determines calibration requirements for instruments
 Establishes calibration procedures
 Develops corrective action procedures
 Documents calibration results and activities
 Supports audit trails for calibration system

33. Futures of Calibration System at NCQC
 Identifies instruments that can be calibrated
 Determines calibration requirements for instruments
 Establishes calibration procedures
 Develops corrective action procedures
 Documents calibration results and activities
 Supports audit trails for calibration system

34. References
 www.calibrationlaboratory.in
 www.stqc.gov.in
 www.diety.gov.in
 www.rscalibration.com
 www.wikipedia.com