Force
A 5 MN hydraulic force machine is installed in the EMI Force and Torque Laboratory for the calibration of force measuring devices in both compression and tension, either with increasing forces only, or with both increasing and decreasing forces.
The reference standards of the laboratory are calibrated by NMIs with published CMC, ensuring traceability of the services provided to the SI Units.
Calibrations can be made in accordance with an international procedure standard - such as ISO 376 for force-proving instruments - or with a procedure agreed with the customer.
Fittings are available for the standard metric thread sizes specified in ISO 376, but tension devices with other arrangements can be calibrated if suitable fittings are supplied by the customer (advice is available for the design of such fittings and for the calibration of special-purpose force measuring devices).
Torque
A 1000 N·m torque standard machine for the calibration of torque transducers and reference torque wrenches. Torque can be applied in both a clockwise and anticlockwise direction, with increasing values only, or with both increasing and decreasing values.
Advice is available on the various calibration procedures related to torque measurements, and on the best method of mounting different types of transducer in the EMI torque standard machine. Reference torque wrenches of capacities 10 N·m, 100 N·m and 1000 N·m can be used at a customer’s laboratory to verify the performance of machines that calibrate industrial torque wrenches.
|
instruments |
Mode | Range |
Calibration and Measurement Capability (CMC) (k=2) |
|
Load cells Aircraft weighing load cells |
Compression & Tension (Increasing & Decreasing Force) |
50 to 100 kN 100 to 5000 kN |
0.10% 0.05% |
|
Torque transducers Torque testers |
Clockwise (CW) Anti-Clockwise (ACW) (Increasing & Decreasing Torque) |
0.5 to 1 N.m
1 to 10 N.m
10 to 1000 N.m |
0.1%
0.05%
0.01% |
Pressure
The EMI Pressure Laboratory is equipped with deadweight piston gauge standards that support measurements of gas and oil pressure at very high accuracy (small uncertainty), over a wide range of pressure, in both the absolute and gauge mode. A special pressure standard also provides accurate measurements of small gas and oil differential pressures in the presence of a high line pressure up to 20 MPa.
The reference standards in the laboratory are calibrated by NMIs with published CMC, ensuring traceability of the services provided to SI units.
The laboratory also has a vacuum calibration system with a vacuum chamber that can be heated to 200 °C and evacuated with a turbo pump to achieve a very low value of absolute pressure of around 2 x 10-9 mbar (2 x 10-7 Pa). Depending on the value, the absolute pressure is measured by Ionisation, Spinning Rotor, or Capacitance reference vacuum gauges. These have all been calibrated at PTB, the National Metrology Institute of Germany.
The calibration services provided by the Pressure Laboratory are summarized in the following table:
|
Medium |
Mode |
Range |
CMC |
|
Gas |
Absolute
|
0.01 mPa to 1 mPa 1 mPa to 1 Pa 1 Pa to 9 kPa 9 kPa to 7 MPa |
10% 1% 0.05% 0.0017% to 0.003% |
|
Gauge |
-91 kPa to 14 MPa |
0.0017% to 0.009% | |
|
Differential |
0 kPa to 200 kPa |
0.005% + 9 Pa |
|
|
Oil |
Absolute |
0.2 MPa to 500 MPa |
0.0025% to 0.008% |
|
Gauge |
0.1 MPa to 500 MPa |
0.0025% to 0.008% |
|
|
Differential |
0 kPa to 200 kPa |
0.005% + 9 Pa |