The type of load cell needed is dependent on the primary and secondary elements used to sense force. However, generally speaking, there are five different types of load cells; strain gauge type load cells, hydraulic load cells, diaphragm load cells, spool load cells, and ring type load cells.
A torque wrench is used to when a particular torque is needed to fasten a nut or bolt. The torque wrench was invented in 1918 by Conrad Bahr. He worked for the New York City Water Department at the time he invented it.
The different types of load cells have different advantages and disadvantages, and the one you need will depend on a broad range of factors. For example, hydraulic load cells will operate in negative 60 degrees temperatures, while others will not.
The majority of load cells commonly used utilize the strain gauge technology. The strain gauge technology has been around for over 40 years and has been well established. Many appreciate the dependability or just prefer to continue using what they have used for years despite possible advantages in other technologies.
Load cells provide non-intrusive and highly accurate load measurement data, which means they are often used within a weighing system. Properly installed load cells that are also calibrated can consistently achieve accuracies within 0.03% to 1%. The variance is impacted by the type of load cell used.
These instruments need to be frequently recalibrated to maintain accuracy. It is recommended that an instrument goes no more than two years between calibrations at the most. To calibrate an instrument, you need to compare the measurements of two instruments. One of the instruments must be a standard device with a known correctness while the second one is the one you measure it against to compare measurements.
There are custom torque sensors that can exceed the calibration limit. These instruments are only calibrated to 360,000 lbs.in., but can go beyond their nominal capacity. Torque sensor and load cell units have been designed to work under a broad spectrum of temperatures ranging from negative 452 degrees F to 450 degrees F.