How tight is that bottle cap? How stiff is that knob to turn? Many product-testing applications need precise measurement of low turning forces, but standard torque meters can’t be relied on for accurate readings. Instead, you need a low-capacity torque sensor.
S. Himmelstein and Company’s low-capacity torque sensors use the same technology as our larger transducers, but they’re optimized for accuracy and repeatability under low torque conditions.
Measuring Low Torque Values
When measuring low values, it’s essential to separate signal from noise. Slip ring-based torque meters impose additional frictional loads that add inaccuracy. A low-capacity torque meter using rotary transformer technology will always do a better job.
Linearity and noise are other issues to overcome. That’s why you should only use a low-capacity torque transducer from a manufacturer with proven torque measurement.
Building Accuracy Into Low-Capacity Torque Measuring Devices
A precise, repeatable torque meter has three components:
- The strain gages
- A system for getting the signals off the shaft
- Advanced signal conditioning electronics
The signal conditioner supplies a precisely controlled excitation voltage to strain gages embedded in the shaft. These generate small electrical signals in response to shaft torque while ignoring bending and thrust. For maximum sensitivity, our low-capacity torque sensors use a titanium shaft immune to magnetic effects.
Then, instead of slip rings, we apply our rotary transformer technology to get these signals from the shaft. Using a ferrite-free transformer provides additional isolation from potential noise sources.
Last, the signal conditioner performs amplification and filtering on the signals from the strain gages. This creates the useable output, in millivolt or +/-5V ranges.
Low-Torque Applications for Low-Capacity Torque Meters
Many products rely on low but predictable torque-to-turn values for accurate operation, and low-capacity torque meters are essential for testing. Endoscope manufacturing is one such application, where precise torque measurement ensures a doctor has good “feel.” Another, also medical, application is testing of Luer lock devices (used for making leak-free connections).
In the automotive industry, torque-to-turn is a critical quality attribute that must be measured and recorded. Quantifying steering wheel feel is one application, the stiffness of rotary controls another. In automotive and elsewhere, torsion springs are an additional example of when measuring low torque values is necessary.
Features of Low-Capacity Torque Transducers
The MCRT® 48000VB low-capacity torque meter measures up to 25 lbf-in of torque and provides 200% overload capability. The MCRT® 49000VB with 400% overload capability measures up to 12.5 lbf-in. Both provide +/- 5V output and operate off a 10.5–24V supply. When millivolt output is required, look to the MCRT® 28000T and TB models, both with 200% overload. For 400% overload, move to the MCRT® 29000TB torquemeter.
One feature these low-capacity torque sensors all share is excellent noise immunity. Many testing environments suffer from high EMI levels, but our products are engineered to minimize any interference.
Specialists in Low-Capacity Torque Measurement
Obtaining accurate, repeatable torque measurements is especially challenging when forces are low. Our low-capacity torque sensors use rotary transformer technology coupled with EMI hardening to produce test results you can trust.
Based in Hoffman Estates, Illinois, we’ve built nothing but torque meters since the 1960s and our experience is second-to-none. With our machine shop and an ISO 17025-accredited laboratory, we keep control over every aspect of manufacture. That’s how we can stand behind our products and deliver exceptional after-sales service.
To learn more about how we can help you measure low torque values, contact us today. We’re always happy to talk about torque.