Introduction to load cell care and calibration
A load cell is the main component used in digital weighing scales and similar devices. A load cell is a sensor which converts the amount of force placed on it into an electrical output or measurement. Load cells measure according to the method by which they detect the weight of an object. For example, a hydraulic load cell works according to the amount of pressure exerted by the internal fluid in measuring the weight of an object. A strain gauge, on the other hand, converts force applied into measurement using a gauge that is attached to the load cell. In addition to these two types of load cells, other kinds include:
- Shear beam
- Single point
- Bending beam
- S type
Each of these kinds of load cells has a different working principle in using force to produce an output.
How to properly take care of a load cell
Since a load cell is a measuring instrument, it is highly sensitive and requires regular maintenance. Apart from load cell calibration, you need to ensure that the weighing scale is used correctly to prevent downtime and minimize the cost of repairs or replacement. In using a load cell, keep in mind the following reminders:
- The weighing capacity should match the object being weighed.
- Use the product in a suitable working environment
- Calibrate load cells regularly
- Monitor both storage and operating temperature
- Be careful in installing and using the load cell
It is also necessary to clean load cells regularly. Dust, dirt, and other contaminants will eventually cause the device to malfunction. In cleaning a load cell, use a clean, dry cloth to remove dirt build-up in and around the connection points.
Knowing when to calibrate load cells
You will not find many suppliers or load cell manufacturers that specify when to calibrate a load cell. The reason for this is because applications can significantly vary, and re-calibrating a load cell depends on many factors. It is also possible that similar kinds of load cells made by different companies may differ in stability and performance.
Although there is no recommended frequency or period of recalibration, experts recommend to do it at least once a year. This way, you can ensure that the load cell works according to the specifications required by the application.
There are times when a load cell is installed with the assumption that it will continue to work for a long time. Unfortunately, all sensors are subject to wear and tear. The product design, as well as the nature of the application all, contribute to how frequent a load cell needs calibration. Whether a load cell requires calibration more often than once a year depends on the need. Factors such as exposure to extreme temperature, ageing, vibration, and other elements all affect the need to calibrate a load cell.
As much as possible, coordinate with the load cell manufacturer so that they can guide you in determining the effects of a variety of factors on the load cell’s performance.