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Mass Standards - Calibration Services
Ordering Calibrations
Services
Mass pieces, or weights, are calibrated using a wide variety of balances
and comparators. These devices are force comparators and provide the raw
data for mass comparisons. Computational tools, notably software developed
at NRC, permit accurate, traceable calibration of weights. The computations
take into account important environmental influences, particularly air
density. The most significant determinations are the estimates of variances
and their propagation through the mass chain.
The Mass Standards Group calibrates all stable materials, particularly
brass and stainless steel. Weights must be in good condition and must
not be too sensitive to environmental conditions, e.g., not porous, and
of adequate surface finish.
 Calibration
Range
Uncertainties
Fees
for Service
Contact:Dr. Claude Jacques
Tel. (613) 993-9330
The normal mass calibration range is from 1 mg to 50 kg. Uncertainties
of measurement range from 40 parts in 109 at 1 kg to 2 parts in 107 at
50 kg. Calibration at routine higher uncertainties should be arranged
through laboratories accredited by the Standards Council of Canada (SCC)
and the NRC's Calibration Laboratory Assessment Service (CLAS). A list
of these laboratories is available. Sets of weights typically range from
1 mg to 100 g. They are calibrated by closed orthogonal designs using
NRC standards.
The results of all mass calibrations normally represent conventional
mass, i.e., the mass an artifact would appear to possess at an air density
of 1.2 kg/m3. All uncertainties are expressed so as to relate the calibrated
mass value to that of the international prototype of the kilogram. Absolute
masses (the mass that a weight would appear to have a vacuum) are also
determined when the densities are known.
Uncertainties on the order of 2 parts in 106 or better require a separate
determination of density. This information can either be supplied by the
client or established by NRC as a separate procedure. NRC will be the
sole arbiter of acceptability of any density estimate from an external
source. NRC does not calibrate, repair, or certify balances or comparators.
The uncertainties quoted in the descriptions below are expanded uncertainties
representing a confidence level of approximately 95%, except where otherwise
indicated. They were obtained assuming a normal distribution and multiplying
the standard uncertainty (one standard deviation) by a coverage factor
of k = 2.
Ordering Calibrations
Services NEW procedures effective March 23, 2006.
A33-05-00-00
Custom Mass Standards Measurements or Services
Fee on request |
Contact
Dr. Claude Jacques for
further information |
A33-05-00-01
Handling Fee
$150 |
A charge is levied for
any instrument or artifact found to be unsuitable for calibration.
This fee covers opening, inspection and return and is based on the
work done prior to discovery of the fault. |
Mass
Magnetic
Susceptibility of Weights
Hydrometers,
Density & Volume
Pressure
Flow
| Mass |
A33-05-01-01
Single Weights
$173 |
Single weights in the range of 1 mg
to 50 kg are calibrated in terms of the working standards of NRC with
an uncertainty of one part in 105, by direct one-on-one
comparison. |
A33-05-01-03
Loading Weights for Dead Weight Gauges
$88 |
Calibration of loading weights for
dead weight gauges is carried out directly traceable to national standards
with an uncertainty of 1 part in 104. |
A33-05-01-06
Reference Kilograms
$680 |
Reference kilograms of adequate quality
are compared with NRC primary stainless steel reference standards
using the NRC primary kilograms comparator. Conventional corrections
are supplied with an uncertainty of 40 µg (40 ppb). |
A33-05-01-08
Reference Kilograms, Comprehensive
$1368 |
Includes mass calibration as per A33-05-01-06
plus determinations of density, height of centre of mass, and magnetic
susceptibility. The variation of the height of the centre of
mass can effectively alter the apparent mass of the
1 kg weight by 3 µg to 5 µg. High magnetic susceptibility renders
a weight unfit for calibration. |
A33-05-01-10
Weight Set
$3284 |
Calibration
of a set of OIML E1 weights, 1 mg to 100 g. |
A33-05-01-20
Centre of Mass
$170 |
Determination of the height of the
centre of mass of a kg reference weight. See A33-05-01-08. |
The accuracy of mass measurement can be greatly affected
by the magnetic susceptibility of weights. For high accuracy and conformance
to a class (E1 to E2 and some ASTM classes), it is important to verify
that magnetic susceptibility is sufficiently small.
A33-05-01-30
Disc Samples
$201 |
Determination
of magnetic susceptibility of a disc sample greater than 30 mm in
diameter. |
A33-05-01-32
Additional
Disc Sample
$133 |
As per A33-05-01-30, for each additional
disc sample of the same dimensions when supplied at the same time. |
A33-05-01-34
Light Weights
$201 |
Determination
of magnetic susceptibility of an OIML- or ASTM- shaped weight (50
g to 2 kg). |
A33-05-01-36
Additional
Light Weight
$133 |
As per A33-05-01-34, for each additional
weight of the same dimensions when supplied at the same time. |
A33-05-01-38
Heavy Weight
$269 |
Determination
of magnetic susceptibility of an OIML- or ASTM- shaped weight (3 kg
to 10 kg). |
A33-05-01-40
Additional
Heavy Weight
$184 |
As per A33-05-01-38, for each additional
weight of the same dimensions when supplied at the same time. |
A33-05-01-42
$50 (set-up)+ $10/weight |
Magnetic susceptibility - Test for compliance |
The derived quantity of density is generally measured in
terms of the water or silicon standards. The densities of liquids and
solids, particularly weights, are determined. Precision pycnometers are
calibrated traceable to primary base SI quantities. Air densities are
routinely computed and are used in aerostatic density measurements, when
necessary. Results are based on calculations made at
20 °C unless otherwise requested by the client.
Hydrometers are calibrated only during the first week of May. Densities
of weights are determined only during the second weeks of May and September.
NRC calibrates sensitive hydrometers graduated in any type of unit. Each
hydrometer must have a serial number and be made of either glass or metal.
Hydrometers in the density range of 475 kg/m3 to 1800 kg/m3 are calibrated
with an uncertainty of 1 part in 103, depending on the quality of the
hydrometer. Calibrations are carried out by hydrostatic weighing in doubly
distilled de-ionized water. If the hydrometer reading is affected by the
surface tension of the liquid into which it is placed, the applicable
surface tension value must be specified.
A33-05-02-00
Setup
$340 |
Preparation
and installation of a batch for calibrations. |
A33-05-02-01
Hydrometers
$236 |
Calibration of one hydrometer at 3
measurement points. |
A33-05-02-02
Additional point on a hydrometer
$84 |
Additional points on the stem are measured
on a hydrometer calibrated through A33-05-02-01. |
A33-05-02-03
Densities of Weights
$519 |
Densities of weights in the range of
7 500 kg/m3 to 17 000 kg/m3 with masses of 10
g to 1 kg are determined hydrostatically with an uncertainty of 2
parts in 103. The densities are traceable to the water
density standard and the national prototype of the kilogram. Lower
levels of uncertainty may be obtained by special arrangement. |
A33-05-02-03A
Additional Weights
$170 |
As per A33-05-02-03, for each additional
weight of approximately the same mass when supplied at the same time. |
A33-05-02-04
Densities of Liquids 600 kg/m3
- 2000 kg/m3
$334 |
Densities of liquids in the range of
600 kg/m3 to 2000 kg/m3 are determined by hydrostatic
weighing using de-ionized doubly distilled water as a density standard
and fused silica artifacts as solid transfer standards. Samples must
be clearly marked. Special arrangements must be made for samples which
are corrosive, volatile at ambient temperatures, toxic or very viscous.
Solutions of thallium compounds are not accepted for calibration. |
A33-05-02-05
Densities of Liquids 1000 kg/m3
- 1800 kg/m3
$624 |
Densities of liquids in the range of
1 000 kg/m3 to 1 800 kg/m3 are determined as
in A33-05-02-04 or gravimetrically using pure water as a reference
standard by means of calibrated pycnometers. |
A33-05-02-06
Determinations of Volume
Fee on request |
Determination of the volume of volumetric
glassware, pycnometers, constant volume delivery devices, syringes,
and other devices is performed gravimetrically. Due to the variety
of such devices and the range of complexity in their volumetric calibration,
this work is undertaken only by special arrangement. |
The primary pressure standard is embodied in a mercury manometer
which serves as the means of realization of the derived SI unit of pressure,
the pascal (Pa). Dead weight piston gauges, also known as piston gauges,
piston-cylinder gauges or pressure balances, provide traceable overlapping
standards to higher pressures.
Clients should refer to "Ordering Calibration Services" in
the Calibration Services pages for general information about shipping.
In addition, the following points should be observed when sending pressure
balances to NRC for calibration.
- It is generally unnecessary to ship the frame of the device.
- Separate the piston from the cylinder and clean both thoroughly, using
warm soapy water. Rinse well and finish cleaning using 95% reagent grade
ethanol or isopropanol.
- Pack the piston and cylinder carefully and separately in their own
container or containers. This is particularly important when they are
shipped with the loading weights.
- If the piston and weight carrier can be separated, be sure that the
carrier is included in the shipment. NRC personnel will not attempt
to separate seized assemblies that appear to have an interference fit.
(A33-05-03-01 to A33-05-03-06)
A33-05-03-01
Dead Weight Gauges, medium accuracy
$1339 |
Routine
evaluation of the areas of dead weight assemblies (piston-cylinder
assemblies) are carried out, with uncertaintaies ³ 0.01%, by comparisons
with reference dead weight gauges traceable to the primary mercury
manometer. |
A33-05-03-01A
Dead
Weight Gauges, high accuracy
$2635 |
Routine evaluation of the
areas of dead weight assemblies (piston-cylinder assemblies) are carried
out, with uncertainties < 0.01%, by comparisons with reference
dead weight gauges traceable to the primary mercury manometer. |
A33-05-03-06
Pneumatic Pressure Gauges
$1740 |
Vibrating cylinder gauges, quartz bourdon
gauges, liquid-in-glass manometers, and barometers and micromanometers
are calibrated with an uncertainty of 0.01%. |
(A33-05-03-21 to A33-05-03-24)
High pressure calibration is performed in the range from 200 kPa to
280 MPa using either a primary pressure balance or a reference dead weight
standard with the indicated uncertainties. Zero and general stability
tests, linearity tests, and points in excess of 10 required can be done
for an additional fee. Please inquire directly about these and other special
calibration requirements.
A33-05-03-21
Hydraulic Pressure Gauges
$1790 |
Vibrating
cylinder gauges, quartz bourdon gauges, etc., are calibrated with
an uncertainty of 0.01% using reference dead weight tester. |
A33-05-03-22
Dial
Gauges
$650 |
Bourdon type gauges are calibrated using
reference dead weight testers. Calibration uncertainty depends upon
the gauge being calibrated. |
A33-05-03-23
Dead Weight Gauges
<100 MPa
$2575 |
Routine
evaluation of the areas of piston-cylinder assemblies are carried
out, with uncertainties < 0.01% by comparisons with reference dead
weight gauges traceable to the primary mercury manometer. |
A33-05-03-24
Dead Weight Gauges
> 100 MPa
$1295
|
Routine evaluation
of the areas of piston-cylinder assemblies are carried out, with uncertainties
> 0.01% by comparisons with reference dead weight gauges traceable
to the primary mercury manometer. |
Gas flow is measured using a volume displacement apparatus using air
or inert reference gases such as nitrogen or argon. Because of the nonlinearity
of flow devices, ten calibration points are recommended over the useful
range of an instrument.
A33-05-05-01
Gas Flow Gauge
$620 (set-up) + $105 per point |
Gas
flow gauges are calibrated for flows of 1 ml per minute to 50 standard
litres per minute, with an uncertainty of 2%. |
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