Tractel Dynafor Expert Wireless Digital Dynamometer

The Tractel Dynafor Expert is a wireless digital dynamometer for high-precision force and weight measurement from 0.5 t to 10 t. It is designed and manufactured by Tractel and uses a strain-gauge sensor read by a built-in microprocessor, which sends the reading by 2.4 GHz radio and Bluetooth Low Energy to displays and software. The manufacturer quotes 0.1 percent accuracy, which makes it the most accurate of the three Dynafor load cells covered in the Tractel range described here, and it is intended for overhead weighing, proof testing, load balancing and force measurement in research and development.

What the wireless link allows

With radio and Bluetooth chipsets available at all times, the Expert reaches the Dynafor HHD handheld display, the AL63 and AL128 large wireless displays and the Dynasoft software accessories at up to 400 m in open field, and any smartphone running the free Dynafor app at up to 30 m. The operator can therefore stand clear of the load while reading the value, and data from the HHD can be downloaded or monitored in real time with Dynasoft. The Dynafor DMU accessory manages thresholds. The unit runs on three AA batteries for 300 to 1000 hours depending on use, and its water-resistant construction is rated IP64 with an IP67 option, which then carries the 0.2 percent accuracy figure.

Technical specifications

Models, codes and dimensions

The model table is from technical sheet T-7052. Weight is listed on the sheet as 2.3, 3.35 and 6.45 kg for the three size groups; consult the sheet for the group assignment of each capacity.

Using a load cell in a lifting set-up

Select the load cell whose WLL is at least the maximum load and at least ten times the smallest load to be measured, because the minimum load is 10 percent of the WLL. Fit it in line with a standard bow or clevis shackle at each end, keep the load in line with the pin axis and avoid side loading. A dynamometer is a measuring instrument, not a lifting accessory in itself, so confirm that it is rated and rigged within the capacity of the system and that the test load is not exceeded; the sheet lists test loads of 1.5 times the WLL. Before ordering, confirm capacity, IP64 or IP67 option, the display needed (HHD, AL63/128, app) and whether a calibration certificate is required. Use of radio equipment is regulated, so check the frequency requirements for the country of use.

Preparing the Dynafor Expert for a test

Before each job, look over the load cell body, the pin holes and the shackles for cracks, deformation, corrosion or wear, and take any doubtful item out of service. Check that the shackles are correctly sized for the pin and the capacity, that the pins are fully engaged and that nothing in the rigging can bear against the body of the dynamometer. Switch the unit on, confirm that the reading is stable with no load and pair it with the display or app that will be used before the lift begins, not while the load is already suspended.

Agree with the lifting supervisor how readings will be communicated, who is allowed to stand where, and at what reading the lift will be stopped. The wireless link keeps the operator away from the load, so plan the exclusion zone around the suspended load rather than around the display.

Proof testing and overhead weighing in practice

Apply the load slowly and steadily; sudden snatching or swinging adds dynamic force that distorts the result and stresses the rigging. During proof tests, increase the load in steps and hold at each step long enough to read a settled value. Use Peak Hold when the highest force during a movement matters, and normal mode when a stable static value is needed. Keep a written or exported record of the readings with date, equipment tested and operator, so the results can be traced later during audits.

Operating in Gulf heat, dust and humidity

Outdoor test sites in Oman can exceed the upper operating temperature on the sheet when equipment is left in direct sun, especially on steel decks and in vehicle cabs. Keep the load cell and display shaded until use and allow them to settle before taking critical readings. Fine dust and sand get into shackle pin holes and threads, so wipe them clean before assembly. Near the coast, salt air and humidity encourage corrosion on steel parts; dry the unit after use and store it in its case in a dry place. Choose between the IP64 and IP67 versions with the real exposure in mind, including spray, rain and wash-down.

Batteries, storage and periodic calibration

Replace the AA batteries before an important test rather than waiting for them to run out mid-lift, and remove them if the unit will be stored for a long period. Store the dynamometer away from heat sources and heavy vibration. Because the instrument is used to verify lifting equipment, its own accuracy must be traceable: follow the calibration interval set by your quality system or local lifting regulations and keep the certificates with the equipment register.

Documents and quotation

The technical sheet is attached; the manufacturer also lists a manual. Seven Star LLC is an independent supplier and quotes the load cell with the display and shackles needed. Related equipment is listed in Material Handling and Lifting Equipment.