Thermometer and Hydrometer Calibration Services
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please click here.
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Click on the question and we will show you the
answer!
Why
is it necessary to have my calibrated thermometer or hydrometer recalibrated?
When
a glass thermometer is heated, the liquid within the bulb expands and is
forced upward into the capillary where its level indicates the temperature
value. Each heating and cooling cycle imparts tremendous stress to the bulb.
After repeated use, even the highest quality liquid in glass thermometer will
undergo a slight change in bulb volume due to this expansion and contraction.
When a change of
this type does take place, the indication of the thermometer will also change.
Recalibration of the certified thermometer updates the indications and thus
allows the user to maintain accurate, reliable and consistent results when
making temperature measurements.
Electronic digital
thermometers are also subject to change in indication: from sensor drift, from
vibration and shock from routine handling, or from less obvious causes such as
aging or deterioration of components.
Recalibration at
regular intervals to document traceability to NIST is an important part of
most quality programs such as the ISO 9000 series of quality standards.
Hydrometers experience fewer radical temperature changes, however they are
exposed to extended immersion times in varying liquids which may attack the
glass, plus they are subjected to mechanical stress and abrasion through
handling and cleaning. Moreover, the natural aging process of the glass
further results in minute changes to the dimensions of the instrument. The sum
of these factors, although not visible to the eye, may result in slight
changes in the weight and/or displacement of the instrument and cause it to
change its indication.
As with
thermometers, periodic recalibration is essential to assure the integrity of
your readings and to comply with the requirements of your quality system and
the host of state and federal regulations which may apply to your activities.
For new
thermometers and hydrometers, or for your existing instruments needing
recalibration, our metrology lab can perform the required testing and document
traceability to NIST.
We calibrate
ASTM and other glass lab thermometers, digital thermometers, PRTs, SPRTs,
PT-100 sensors, bimetal and industrial thermometers, glass hydrometers of all
common scales, pipets, burets and other glass volumetric ware.
IMPORTANT!
Our thermometer & hydrometer calibration facility is accredited to ISO/IEC
Guide 25 and ANSI/NCSL Z-540-1-1994. Your ISO 9000 (series) or
other quality program can accept our calibrations without the burden of
conducting site audits or quality surveys. Copies of our Accreditation
Certificate and Scope of Accreditation are available upon request for your
Qualified Supplier files.
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How often
should my thermometer or hydrometer be recalibrated?
This is a complex question.
Consideration should be given to the frequency of use, the temperatures at
which it is used, and the requirements of the regulatory agencies and/or the
quality system you may be using. In general, for most laboratory and
industrial applications a recalibration interval atone year is adequate,
however you should choose a recalibration interval which satisfies your
quality system and then be sure to adhere to it. Most ISO 9000 series programs
are using a one year recalibration interval.
What
does recalibration entail?
• Your
instrument will be examined under magnification for any chips, scratches,
impurities in the bore or other defects which may impair its function.
• The (glass) instrument will
be examined under a polariscope to assure that there is no damage to the glass
from overheating or from overly rapid cooling (thermal shock).
• Any separations of the liquid
will be repaired.
• If the etchings are faded,
the scale will be repigmented.
• Your instrument will be
tested against NIST certified prima,’,’ master standards at the test
points you specify, in accordance with ISO Guide 25, ASTM and NIST test
methods. A new NIST traceable Report of Test will be issued, valid for the
period of time that you specify. This certificate meets the requirements of
ISO/IEC Guide 25, the FDA, the EPA, and the ISO 9000 and 08-9000 series of
quality standards.
• A durable calibration sticker
will be affixed to your thermometer with the date of calibration,
recalibration due date and other appropriate information.
• The instruments are our
responsibility on retum shipment to you. We pack them extremely well, If any
are damaged in transit to you, you will receive a prompt, no charge PRIORITY
replacement. No questions, no hassle.
• Your instrument(s) will be
registered in our calibration database. This will enable us to inform you in
writing one month before the expiration of your calibration certificate that
recalibration is due, and permit us to keep you abreast of any changes in
industry regulations which may affect your calibration.
Choosing Test Points
If your
thermometer has been previously certified, the test points have already been
established. Proceed to the pricing section
below.
If the
instrument to be calibrated is an ASTM instrument, the required test points are
specified by ASTM E-1(for thermometers) or ASTM E-100 (for hydrometers) and may
be found in those publications - or call us at 1-219-271-7020
and we’ll look them up for you! We will calibrate your ASTM instrument to ASTM
specs unless you tell us otherwise.
If yours is not
an ASTM instrument, and has never been certified you can let us choose
the most suitable test points or you may wish to specify those test
points to us.
To assist you in
choosing test points, we present the following considerations,
which are drawn from ASTM and NIST recommendations:
1.
A minimum of three temperatures should be calibrated, generally low,
medium and high on the scale of the instrument.
2.
There should be no more than 100 graduations between any two calibrated
temperatures.
3.
If the temperatures used by the manufacturer for scale placement are
known, the temperatures used for calibration should correspond. This will assure
linearity of spacing between the calibrated points, therefore allowing the user
to interpolate intermediate values.
PRICING
Calibration charges are determined in accordance with the
following schedules:
THERMOMETERS
Prices indicated are per point tested |
| From -80°
to < -37°C
From -112°
to < -35°
F
$83.50 |
| From -37°
to < 0°
C
From -35°
to <32°
F
$61.00 |
| From
0°
to100°
C
From 32°
to 2l2°
F
$40.00 |
| From 100°
C to200°
C
From >212°
to 392°
F
$50.00 |
| From >200°
to 300°
C
From >392°
to 572°
F
$60.00 |
| From >200°
to 370°
C
From >572°
to 700°
F
$84.00 |
| From >370°
to 400°
C
From >700°
to 770°F
$108.00 |
|
HYDROMETERS
should always be calibrated at three points:
low medium and high on the scale. |
From .620 to < .670
SG & equivalent in other
$49.00
scales (Over 80 API) |
|
From .670 to 1.600 SG & equivalent in other
$41.00
scales (All other API ranges) |
| From 1.600 to 2.000 SG
& equivalent in other scales
$49.00 |
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How do I arrange
for my thermometer or hydrometer to be recalibrated?
Call us and we will
arrange all transportation. We will pick up the instrument(s) or alternatively,
we can UPS you a specially designed, reusable shipping case into which you place
the instrument(s), snap the case closed, affix the supplied return label, and
ship it back to us via the carrier of your choice.
I
have an upcoming audit. How much time do you need?
Normally 5
working days at our facility. If you have an emergency, let us know and we will
make certain your deadline is met.
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