Physikalisch-Technische Bundesanstalt (PTB)

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Working group 1.22

Realization of Torque

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- Calibrations

1 N·m Torque Standard Machine
1 kN·m Torque Standard Machine
20 kN·m Torque Standard Machine
1.1 MN·m Torque Standard Machine
20 N·m Torque Calibration Machine
2 kN·m Torque Calibration Machine
5 kN·m Torque Calibration Machine
1000 W Rotary Power Measurement

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Measuring Devices

1 N·m Torque Standard Machine
1 kN·m Torque Standard Machine
20 kN·m Torque Standard Machine
200 kN·m and 1 MN·m Torque Standard Machine

20 N·m Torque Calibration Machine
2 kN·m Torque Calibration Machine
5 kN·m Torque Calibration Machine

1000 W Rotary Power Measurement

Adaptation recommendations

1 N·m Torque Standard Machine

Short name	1-N·m-DmNME
Nominal torque	1 N·m
Rel. exp. (k=2) uncertainty	1·10^-4
Torque steps	1, 2, ..., 10 mN·m 10, 20, ..., 100 mN·m 20, 40, ..., 200 mN·m 50, 100, ..., 500 mN·m 100, 200, ..., 1000 mN·m
Remarks	By combining different steps for clockwise and anti-clockwise torque, an additional step-down to a ratio 1:100 is possible for some ranges.

1 kN·m Torque Standard Machine

Short name	1-kN·m-DmNME
Nominal torque	1 kN·m
Rel. exp. (k=2) uncertainty	2·10^-5
Torque steps	1, 2, ... , 10 N·m 2, 4, ..., 20 N·m 5, 10, ..., 50 N·m 10, 20, ..., 100 N·m 20, 40, ..., 200 N·m 50, 100, ..., 500 N·m 100, 200, ..., 1000 N·m
Remarks	By combining different steps for clockwise and anti-clockwise torque, an additional step-down to a ratio 1:100 is possible.

20 kN·m Torque Standard Machine

Short name	20-kN·m-DmNME
Nominal torque	20 kN·m
Rel. exp. (k=2) uncertainty	2·10^-5
Torque steps	100 N·m to 20 kN·m in 100 N·m steps
Remarks	-

220 kN·m and 1.1 MN·m Torque Standard Machines

Short name	1,1-MN·m-DmNME
Nominal torque	220 kN·m or 1.1 MN·m
Rel. exp. (k=2) uncertainty	1·10^-3 (Range 200 kN·m: 4 kN·m to 20 kN·m and Range 1 MN·m: 20 kN·m to 100 kN·m) 8·10^-4 (Range 200 kN·m: 20 kN·m to 200 kN·m and Range 1 MN·m: 100 kN·m to 1000 kN·m)
Torque steps	220 kN·m measuring range: continually in the range from 4 kN·m up to 220 kN·m 1.1 MN·m measuring range: continually in the range from 20 kN·m up to 1.1 MN·m
Remarks	The forces acting on the two-armed lever are measured by means of force transducers. The machine has a vertical measuring axis.

20 N·m Torque Calibration Machine

Short name	20-N·m-DmKE
Nominal torque	20 N·m
Rel. exp. (k=2) uncertainty	4·10^-4 (Range: 0.1 N·m to 20 N·m) 2·10^-3 (Range: 1 mN·m to 0.1 N·m)
Torque steps	Continually in the ranges from 1 mN·m up to 0.1 N·m and 0.1 N·m up to 20 N·m
Remarks	Calibration machine with reference transducer for automatic continuous measurements.

2 kN·m Torque Calibration Machine

Short name	2-kN·m-DmKE
Nominal torque	2 kN·m
Rel. exp. (k=2) uncertainty	2·10^-4
Torque steps	Continually in the range from 1 N·m up to 2 kN·m
Remarks	Calibration machine with reference transducer for automatic continuous measurements.

5 kN·m Torque Calibration Machine

Short name	5-kN·m-DmKE
Nominal torque	5 kN·m
Rel. exp. (k=2) uncertainty	2·10^-4
Torque steps	Continually in the range from 100 N·m up to 5 kN·m
Remarks	Calibration machine with reference transducer for automatic continuous measurements.

1000 W Rotary Power Measurement

Short name	dyncal100
Nominal power	1000 W
Rel. exp. (k=2) uncertainty	2·10^-3 (absolute 0,2 W)
Modes of operation	turning speed range (5 ≤ n ≤ 150) min^-1 power range (5 ≤ P ≤ 1000) W maximum torque 100 N·m - driving mode: max. control deviation of turning speed 0,1% (absolute 0,1 min^-1) - breaking mode: max. control deviation of power 1% (absolute 1 W)
Bemerkung	Einrichtung für die Kalibrierung von Ergometerprüfständen

Adaptation recommendations

nominal torque	shaft diameter	shaft length	hub diameter	hub length
M_nom	D_a	L_a	d_i	L_i
N·m	mm	mm	mm	mm
<= 20	15_h7	>= 40	19^H7	>= 25
> 20 to <= 100	20_h7	>= 45	25^H7	>= 30
> 100 to <= 500	30_h7	>= 60	38^H7	>= 40
> 500 to <= 2000	50_h7	>= 80	65^H7	>= 60
> 2000 to <= 5000	70_h7	>= 110	90^H7	>= 85
> 5000 to <= 20000	110_h7 or 130_h7	>= 115	155^H7	>= 100

If the design with a hub is selected, depending on the material used, the following minimum wall thicknesses shall be complied with (D_n - outside hub diameter):

material	steel	grey cast iron	aluminium
D_n / D_i	1.5	2.0	2.5

1.1 MN·m Torque Standard Machine
On both sides, a flange adaptation using groove stones in circular ring grooves with the following parameters is specified:

diameter of circular ring groove in mm	500	700	900
maximum torque in kN·m	≤ 350	≤ 700	> 700
maximum number of screws M36 (12.9)	23	30	30

Adapters must be supplied - if not available yet. The thickness of the adapter flange plates* should be in the range from 40 mm to 90 mm. A centering is possible using fitting bore holes with diameter Ø = 20 ^H7 mm and a depth ≥ 20 mm on the adapter side.

Additional specifications for the transducer under test:
- maximum overall mass including adapters*: 2000 kg
- maximum diameter*: 1000 mm
- minimum height*: 600 mm
- maximum height*: 2500 mm
For tightening the screws with a hydraulic wrench, some space is needed near the screw heads on the transducer side.
*) Specifications deviating from the above given values must be agreed individually.