| Purpose
of Calibration |
To
ensure readings from an
instrument are consistent
with other instruments
and to determine the accuracy
of the instrument i.e.
that it can be trusted
for its observed /displayed
measured value. |
| The
value of calibration for
industry |
| 1. |
To
ensure that end
products are manufactured
to specifications |
| 2. |
To demonstrate
that the industry
operates a quality
system technically
competent and are
able to generate
technically valid
results |
| 3. |
To increase quality
& value of product.
|
| 4. |
The
calibrated measuring
instruments (working
standards) have
the assurance
traceable to National
/International
Measuring Standards. |
|
| What
is Traceability? |
Property
of the result of a measurement
or related to stated references,
usually National or International
standards, through an
unbroken chain of comparisons
all having stated uncertainties.
|
| Why
measurements must be Traceable? |
| 1. |
Traceable
measurements ensure
the uniformity of
manufactured goods
and industrial processes.
|
| 2. |
To
support equity in
trade as well as
compliance to regulatory
laws & standards.
|
| 3. |
Essential
to the development
of technology. |
| 4. |
To
provide traceable
calibration of
test and measurement
equipment is an
ISO-9000 requirement
(Purpose: With
an eye to provide
safety and fitness
for use) to ensure
that the products
manufactured in
one country will
be acceptable
in another on
the basis of agreed
to measurement
standards, methods
& practices)
|
| 5. |
Provides
users with assurance
of the confidentiality,
validity and accuracy
of the data provided
while testing. |
|
| Uncertainty
- How accurate are your
measurements? |
It
is a measure of the quality
of a measurement &
provides the means to
assess & minimize
the risks and possible
consequences of poor decision |
(A
measurement with a stated
uncertainty can be compared
to others) |
(Measurements
are traceable when they
can be related to recognized
measurement system through
an unbroken chain of comparisons
each with stated uncertainties.) |
| Calibration
Interval - Validity Period |
Validation
is usually nominal maximum
period between two successive
calibrations. The validity
period is generally considered
to be maximum appropriate,
provided |
|
The
equipment is of
good quality and
is of proven adequate
stability.
|
|
If
any suspicion
or indication
of overloading
or mishandling
arises, the equipment
will be checked
immediately and
thereafter at
frequent intervals
until it can be
shown that stability
has not been impaired.
|
|
The
extension of validity
period is based
on factors such
as history of
stability, frequency
of use, accuracy
required, ability
of staff to perform
regular checks
and successful
participation
in proficiency
testing programs.
It is the responsibility
of the testing
authority to provide
evidence that
its calibration
system ensures
that confidence
in the equipment
can be maintained. |
|
Adequate
records of the test data
must be maintained over
a period of time to draw
support for extension
of validity period. |
| Calibration
Measurement!!! How? |
|
Verifying
the performance
of the test instrument
which involves applying
a standard value
to the instrument
and observing how
it behaves.
|
|
Adjust
the response of
the instrument,
wherever possible(After
verifying response,
reset, adjust/correct
the instrument via
internal control
which in normal
course is not accessible)
. |
|
Obtain
correction factor
for the test instrument.(Accordingly
correction factors/calibration
constants are calculated
& incorporated
in measurements)
|
|
| Nagman’s
Centre
for Calibration provides
valid and accurate measurements
using updated standards
having unbroken chain of
traceability to National
and International Standards. |
