|
|
|
|
Accredited calibration services:
From -196oC to 1000oC ASTM thermometers, digital thermometers, PRTs, thermocouples, thermistors
Specific Gravity
hydrometers. API hydrometers, Baume hydrometers,
ASTM Class 1 and OIML E-2 and lesser specification stainless steel and brass laboratory weights. New calibrated weights and re-calibration of weights you currently have.
Thermo-hygrometers, chart recorders, humidity sensors, data-loggers
Burets, pipets, volumetric flasks, graduated cylinders, volumetric glassware
Testing and certification that an instrument complies with specified accuracy requirements...
|
NIST TRACEABLE HYDROMETER CALIBRATION CALIBRATION: The
set of operations which establish, under specified conditions, the relationship
between values indicated by a measuring instrument ....,
and the corresponding known values of a measurand.
from ISO Guide 25, ‘definitions’ CALIBRATION
consists
of the following services: Pre-calibration examination: The hydrometer is inspected visually for defects in numbering, graduating, condition, or any obvious physical defects or damage, for any loose ballast material, and the presence and correct placement of a 'scale slippage indicator'. The
hydrometer is examined under a polariscope to be certain it is free from strains
in the glass (usually from the manufacturing process), as severe strains may
affect the integrity of the instrument in the long term.
cALIBRATION:
PER ASTM E-126 The
instrument is then tested in carefully prepared solutions of appropriate media,
against NIST calibrated
reference hydrometers at the required test
points (as specified by ASTM or the customer). At
least three readings of the clients instrument (and at least six readings of
the NIST reference standard) are taken at each test point. Readings are resolved
under magnification to approximately one-tenth of the
smallest scale division and are carefully noted.
Provision
of documentation: A Report of Test (sometimes called a Certificate of Calibration) is prepared detailing all pertinent information concerning the test, the observed readings of the instrument, (with corresponding corrections), and all the required information to convey NIST traceability. (See photo at right, above) All certificates are laminated in heavy plastic for protection in the laboratory environment.
Sample Calibration Report for Hydrometer
A durable calibration tag is affixed to the hydrometer’s box, or case, indicating the date of most recent calibration and the ‘next due’ date. Recalibration form and address label to send in your instrument for calibration |
