Rotary Torque Transducers

Choose a Product Category
Find Product

Dynamic torque measurement is essential to protect high-value rotating machinery and enable control over torque values. When measurement accuracy is essential, choose a rotary torque transducer from S. Himmelstein and Company. Drawing on more than 50 years of experience and innovation, S. Himmelstein and Company builds rotary torque transducers that give the highest accuracy in real-world environments. 

Types of Rotary Torque Transducers

Our rotary transducers are offered in seven categories: 

  • Compact Digital — 25 to 10,000 lbf-in torque, non-contact, DC-operated.
  • Ultra-Precise Digital — Three overload models plus dual-range model, torque ranges: 25 to 375,000 lbf-in.
  • Low Capacity — Shaft-end models, torque ranges: 10 to 400 ozf-in.
  • Precision Digital — Three overload models plus dual-range model, torque ranges: 25 to 4,000,000 lbf-in, .05 percent accurate analog of shaft torque, .02 percent noise and ripple.
  • Bearingless Digital — Flanged/Disk-style, very high stiffness, easy installation, tolerant of rotor-stator misalignment. Ranges from 250 to 4,000,000 lbf-in.
  • MV/V Analog — Torque ranges: 25 to 4,000,000 lbf-in, mV/V output, compatible with ac carrier amplifiers.
  • DC Analog — Torque ranges 10 ozf-in to 4,000,000 lbf-in.

What Is a Rotary Torque Transducer? 

A rotary torquemeter or torque transducer measures torque in a rotating shaft. Our rotary transducers sense torque with high-precision strain gages. Mounted on or embedded in the rotating element, these respond to shear forces with changing electrical resistance. When configured in a Wheatstone Bridge arrangement, sophisticated electronics convert these signals into torque values. 

Rotating shafts pose a challenge for transducers: How to get the signal to the controller. While slip rings are one approach, we prefer the rotary transformer. In fact, S. Himmelstein and Company invented the rotary transformer specifically for dynamic torque measurement.

The rotary transformer, in both cylindrical and pancake configurations, offers advantages over slip rings: 

  • No friction
  • No wear
  • Immune to intermittent contact problems
  • Operates at higher speeds


Electrical resistance varies with temperature, which can differ widely in rotating plant applications. Strain gages incorporate temperature compensation, but not to the level we demand. That's why S. Himmelstein and Company rotary torque sensors incorporate our superior temperature compensation technology.

Electrical Overrange

By engineering significant electrical overrange into our amplified output rotary transducers, we avoid peak clipping. This ensures our transducers provide accurate torque measurement, even beyond full scale. Rotary sensors are available in models with overrange from 130 percent to 300 percent.

Mechanical Overload 

All rotary torque meters are designed with significant mechanical overloads as safety factor from unexpected occurrences. Models are available with rated overloads from 200% to 1,000% of their rating. This allows both protection and optimal sizing of the sensor for the application.

Common Applications for Rotary Torque Transducers 

We build rotary transducers for measuring torque values from 25 lbf-in (select models go lower) up to 4,000,000 lbf-in. These are used in industries ranging from automotive and aerospace manufacturing to steel and paper-making and chemical processing.

Inspection and testing of torque-tightening equipment is one application area. Confirming power tools tighten fasteners to the specified degree helps guarantee products will give reliable service and perform safely. 

Torque is a key indicator of equipment performance and process stability. In motor-driven equipment such as fans, pumps and compressors, torque measurement protects against damage and provides data for process control. Low torque in a pump might indicate an unloaded condition, while excessively high torque in a mixer could indicate a viscosity problem.

Torque measurement helps protect against equipment damage, avoiding downtime or by enabling safe shutdown. That's why our rotary torque sensors are used wherever there are pumps, motors and rotating shafts.

To learn more about our complete offerings, contact us today.