TensitronTensitron Products, Manufacturing Tension Meters Since 1935  
Precision Tension Meters and Tension
Measuring Instrumentation Since 1935
733 S. Bowen St.
Longmont, CO




For moist materials or operation in a damp atmosphere, the Model "RT" Series has internal parts made of stainless steel, plastic, gold-plated steel, copper and other materials and treatments which minimize the damage due to moisture. Although this instrument is not waterproof, it should give excellent service under conditions where it is exposed to an occasional spray. All trigger meter tension ranges are available in the "RT" Series. 


Downloadable Files: TR Datasheet

*Go To DIGITAL Wire & Filament Tension Meters.


Trigger Tension Meters

The Trigger Tension Meter measures tensions on wires, yarns, fiber optics, films, tapes, narrow fabrics and flat materials. The contact elements are recessed into the trigger shield, which stops material from snagging and/or breaking behind the rollers. Internal magnetic dampening assures an accurate tension reading no matter which position the meter is held in.

  • Portable
  • Versatile
  • Lightweight
  • Easy Operation
  • Automatic Guides
  • Durable Construction
  • Magnetic Dampening
  • Can Be Permanently Mounted
  • Right- or Left-Hand Operation

Our instruments are utilized extensively in the major wire, textile, coil winding, EDM, fiber optic and synthetic materials industries. We have established a reputation for providing quality instruments which endure rigorous industrial and test applications.

Tensitron has been manufacturing precision tension meters since 1935. The popularity of the Trigger Meters is due in part to their proven durability - our customers know they can count on using them for many years. We often ship the same day we receive your order!

Tensitron repairs and recertifies all of its meters. We regularly receive units which are 10-25 years old. We offer a quick turnaround time, plus you receive the appropriate calibration certification for today's industry standards at no extra charge.  


EDM Wire Applications Tensitron, Inc. has a long time association with the wire EDM industry, dating back to the original American prototypes for this technology. Special EDM calibrations of our tension meters are performed to insure utmost accuracy for the instrument to the wire type. Typically these calibrated values mimic the calibration protocol for the Wire EDM machine and therefore help to insure maximum accuracy of wire tension throughout its entire tension range. We are quite familiar with the requirements of measuring tensions on different types of EDM wires and are happy to make a recommendation for your specific application.

As a general rule of thumb, most mechanical tension meters must be calibrated to the specific EDM wire being used, to ensure accuracy. The Digital Tension Meter, P/N: TX-5EDM already includes multiple calibrations for many different EDM wire sizes. If using the less expensive mechanical tension meter, we recommend our model P/N: TR-4000 specially calibrated to your wire size. For greater accuracy, flexibility, and ease of use we recommend our model TX-5EDM for EDM wire applications. 

Model "TR" Series

Range In Grams Use Model Number
25 g TR-25
125 g TR-125
250 g TR-250
1000 g TR-1000
2000 g TR-2000
4000 g TR-4000
5000 g TR-5000


Narrow Web & Tape Applications

Our Trigger Tension Meters, Model "TM" series are commonly used to measure tension in flexible, thin tapes and webs. The 1" cylindrical rollers can be clipped onto the edge of moving materials to easily give per linear inch (pli) tension readings up to 5000 grams (over several models).

Standard Contact Elements


Model "TM" Series

Range In Grams Use Model Number
With 1/2" Cylindrical, Scooped or Flanged Rollers
250 g TM-250
With 1/2" or 1" Cylindrical, Scooped or Flanged Rollers
1000 g TM-1000
2000 g TM-2000
4000 g TM-4000
5000 g TM-5000



Universal Mounting Bracket

All Trigger Tension Meters can be mounted in a fixed position for in-line tension monitoring by means of an UNIVERSAL MOUNTING BRACKET which is sold separately. The mounting bracket allows either intermittent or continuous readings, as required.




Operating Instructions

Squeeze the trigger to separate the three rollers. Insert material (yarn, wire, web, etc.) between the contact elements so it rests against the trigger shield and slowly release the trigger. The center roller deflects as the tension in your material increases. As the pointer makes its first revolution read the BLACK outer dial for the correct tension. Should tensions increase and the pointer begin a second revolution, read the RED inner dial. To release the material, slowly squeeze the trigger and remove the tension meter.


Safe Operating tension reference table and recommended Tension Meter for annealed copper wires.

AWG Inch Safe Tension Model No.
48 - 52 .0013 - .008 9 - 3 g TR-25
43 - 47 .0022 - .0014 27 - 11 g TR-125
39 - 42 .0035 - .0025 66 - 34 g TR-250
35 - 38 .0056 - .0039 166 - 84 g TR-1000
30 - 34 .0100 - .0064 560 - 206 g TR-2000
27 - 29 .0142 - .0113 1100 - 730 g TR-4000
24 - 26 .0201 - .0159 2265 - 1100 g TR-5000



The right tension for a yarn is in the vicinity of .15 to .35 grams per denier. If you are using a rayon yarn which is running 100 denier 40 filament, tensions probably lie between 15 and 35 grams. Safe tensions change with the material of the yarn and its number of filaments. (E.g., nylon requires a lower tension while cotton permits the use of higher tension). For proper coverage of 15-35 grams, the model TR-125 instrument is recommended.