Mass standards

Calibration range

The normal mass calibration range is from 1 mg to 64 kg. Uncertainties of measurement range from 40 parts in 109 at 1 kg to 2 parts in 107 at 60 kg. Calibration at routine higher uncertainties should be arranged through laboratories accredited by the Standards Council of Canada and the NRC's Calibration Laboratory Assessment Service.

The results of all mass calibrations normally represent conventional mass, i.e., the mass an artefact would appear to possess if it had a density of 8,000 kg/m3 measured in 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 in the absence of air buoyancy) are also determined but may have a larger uncertainty depending upon how well the densities of the mass artefacts 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. The NRC will be the sole arbiter of acceptability of any density estimate from an external source. The NRC does not calibrate, repair or certify balances or comparators.

Uncertainties

The uncertainties quoted in the descriptions below are expanded uncertainties representing a confidence level of approximately 95 percent, 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.

Fees for service

If you wish to order a calibration service, please request a quote from the following technical contact:

Dr. Richard Green
Telephone: 613-990-0721
Email: Richard.Green@nrc-cnrc.gc.ca

Note that fees for measurement and calibration services are subject to change. The fees for service quoted do not include shipping, insurance or the cost of a customs broker. The client must arrange and pay for these services separately.

Calibration number Description Fee
A33-05-00-00 Custom mass standards measurements or services Fee on request
A33-05-00-01 Handling fee. A charge is levied for any instrument or artefact 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. $265

Mass

Calibration number Description Fee
A33-05-01-00 Setup. Set up for services A33-05-01**, applies to all. $820
A33-05-01-01 Single weights (masses). For weights up to 64 kg. The charge for A33-05-01-00 also applies. $275
A33-05-01-03 Loading weight for dead weight gauges. Calibration of loading weights for dead weight gauges is carried out directly traceable to national standards, with an uncertainty up to 1 part in 106. The charge for A33-05-01-00 also applies. $150
A33-05-01-06 Reference weights - mass. Reference mass standards of adequate quality and characterization are compared with NRC primary stainless steel reference standards. Conventional corrections are supplied with an uncertainty of up to 40 ppb. The charge for A33-05-01-00 also applies. $1,120
A33-05-01-08 Reference weights, comprehensive. 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. The charge for A33-05-01-00 also applies. $2,250
A33-05-01-11 Weight - one decade set. The charge for A33-05-01-00 also applies. $830
A33-05-01-20 Centre of mass. Determination of the height of the centre of mass of a kg reference weight. See A33-05-01-08. The charge for A33-05-01-00 also applies. $505

Magnetic susceptibility of weights

The accuracy of mass measurement can be 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.

Calibration number Description Fee
A33-05-01-30 Mass artefact. Determination of magnetic susceptibility of a mass artefact of standard shape (disc, OIML, ASTM). The charge for A33-05-01-00 also applies. $505
A33-05-01-32 Additional mass artefact or sample. As per A33-05-01-30, for each additional sample of the same dimensions when supplied at the same time. The charge for A33-05-01-00 also applies. $220

Hydrometers, density and volume

The derived quantity of density is generally measured in terms of water density or that of silicon standards. The densities of liquids and solids, particularly weights, can be determined. Results are based on calculations made at 20 °C unless otherwise requested by the client.

The 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 1,800 kg/m3 are calibrated with an uncertainty of 1 part in 103, or better 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.

Calibration number Description Fee
A33-05-02-00 Setup. Preparation and installation of a batch for calibrations. This charge applies to every batch (up to 20 units) of services A33-05-02-01, A33-05-02-03, A33-05-02-05. $820
A33-05-02-01 Hydrometers. Calibration of one hydrometer at 3 measurement points. The charge for service A33-05-02-00 also applies. $390
A33-05-02-03 Densities of weights. 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 two 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. The charge for service A33-05-02-00 also applies. $790
A33-05-02-05 Densities of liquids in the range of 600 kg/m3 to 2,000 kg/m3. Densities of liquids in the range of 600 kg/m3 to 2,000 kg/m3 are determined hydrostatically, gravimetrically, or by comparison using pure water as a reference standard. The charge for service A33-05-02-00 also applies. $850
A33-05-02-06 Determinations of volume. 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. Fee on request

Pressure

The primary pressure standard is embodied in a mercury manometer that 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.

Preparation and shipping

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 the NRC for calibration.

  • Separate the piston from the cylinder and clean both thoroughly, using warm soapy water. Rinse well and finish cleaning using 95 percent 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.

Pneumatic pressure calibrations

Calibration number Description Fee
A33-05-03-01 Dead weight gauges, medium accuracy. Routine evaluation of the areas of dead weight assemblies (piston-cylinder assemblies) are carried out, with uncertainties > 0.01 percent, by comparisons with reference dead weight gauges traceable to the primary mercury manometer. $2,185
A33-05-03-01A Dead weight gauges, high accuracy. Routine evaluation of the areas of dead weight assemblies (piston-cylinder assemblies) are carried out, with uncertainties < 0.01 percent, by comparisons with reference dead weight gauges traceable to the primary mercury manometer. $4,300
A33-05-03-06 Pneumatic pressure gauges. Vibrating cylinder gauges, quartz bourdon gauges, liquid-in-glass manometers, barometers and micromanometers are calibrated with an uncertainty of 0.01 percent. $2,865

Hydraulic pressure calibrations

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.

Calibration number Description Fee
A33-05-03-21 Hydraulic pressure gauges. Vibrating cylinder gauges, quartz bourdon gauges, etc., are calibrated with an uncertainty of 0.01 percent using reference dead weight tester. $2,935
A33-05-03-22 Dial Gauges. Bourdon type gauges are calibrated using reference dead weight testers. Calibration uncertainty depends upon the gauge being calibrated. $1,065
A33-05-03-23 Dead weight gauges < 100 MPa. Routine evaluation of the areas of piston-cylinder assemblies are carried out, with uncertainties < 0.01 percent by comparisons with reference dead weight gauges traceable to the primary mercury manometer. $4,230
A33-05-03-24 Dead Weight Gauges > 100 MPa. Routine evaluation of the areas of piston-cylinder assemblies are carried out, with uncertainties > 0.01 percent by comparisons with reference dead weight gauges traceable to the primary mercury manometer. $2,130

Flow (gas)

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.

Calibration number Description Fee
A33-05-05-01 Gas flow gauge - set up charge. Set up for services A33-05-05-02. $1,010
A33-05-05-02 Gas flow gauge - calibration. Gas flow gauges are calibrated for flows of 1 ml per minute to 50 standard litres per minute, with an uncertainty of 2 percent. The charge for service A33-05-05-01 also applies. $180

Contact

Dr. Richard Green
Telephone: 613-990-0721
Email: Richard.Green@nrc-cnrc.gc.ca

Business Office: MSS-SMEBusiness-Affaires@nrc-cnrc.gc.ca

Date modified: