When you measure forces or loads, in addition to the capacity and size of the load cell, a number of application requirements need to be carefully considered. These include:

• Operating Temperature Conditions (Well controlled, room temperature or outdoor, harsh environments with changing humidity and temperature)
• Duration of measurement (Short term measurement with a Tare or longer term measurements where Tare is not feasible)
• Absolute Accuracy Required (as a percentage of full scale output or as a percentage of reading)
• Direction of loading (tension or compression or both)
• Certifications Needed (for trade applications needing NTEP or OIML certifications or test and measurement needing ASTM E-74 OR R & D)
• Mounting Options (Fasten sensor on both sides or no need for fastening at all)
• Output required (Analog mV/V, 0-5V, 4-20mA, Digital USB, Digital Wireless, Digital RS-232/485)
• Measurement Speed (1Hz or up to 100Hz or faster than 100Hz)
• Total cost of operation (small quantity or large volumes)

Overall we offer two broad categories of load/force/weight measurement solutions: Resistive Load Cells and Capacitive Load Cells

Resistive Load Cells

Resistive load cells are load/weight/force sensors made using strain gauges that are bonded to a metallic member. When the metallic member flexes due to applied loads/forces/weights, then the strain on the strain gauges change that result in a change in the output from a wheatstone bridge network.  Applying a 10V DC input voltage typically results in an output of about 20 mV in the total output from the circuit.

For applications that need high accuracies, NTEP/OIML Certifications, or operate under changing temperature conditions from -10C to 40C and/or need long term stability,  we recommend you use our resistive load cells with either the DI-1000 Series Digital Load Cell Interfaces or the AI-1000 Series Analog Interfaces for your application.

Capacitive Load Cells

Capacitive load cells are very rugged and are great for short duration testing in controlled room temperature conditions.  In general, our capacitive load cells are an excellent integrated solution for short term measurement of forces/loads under room temperature conditions when you can TARE or zero out the readings before measuring the force.

Comparison of Capacitive and Resistive Load Cells