FAQs on load cells

　Is there a standard or specification for the time it takes for a load cell to go from installation to entering the second stage of creep? 　

What brand is good? Export

@The Path Forward: The creep of sensors is something that is not easily taken into account during field applications. Creep is a concept that refers to the change in the output signal of a sensor over a certain period of time, when the sensor is under full load and its weight remains constant. According to national standards, for C3-grade sensors, it should not exceed 0.017%. For example: if the rated range of the sensor is 10 tons, then when a weight of 10 tons is applied to the sensor, its output must not exceed 0.0017 tons within 30 minutes; in other words, it must be less than 1.7 kilograms. This is a fairly strict standard, and it’s likely that sensors from many domestic brands will not meet it. As for the second stage of creep you mentioned, I’m not quite sure what you mean. According to national standards, if the 30-minute creep value does not meet the requirements, then the 2-hour creep value must be considered. Standard test for creep: For a 10-ton sensor, apply a load of 10 tons to it initially, and repeat this application 3 times in succession. After 30 minutes, apply another 10-ton weight to the sensor and begin recording its output values over the next 30 minutes (10 seconds, 30 seconds, 1 minute, 2 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes). The creep parameters also need to be tested at different temperatures: 20 degrees, 40 degrees, and minus 10 degrees. Sensors that meet such requirements also come at a high price. Good sensors require temperature testing, which means their cost is high, and they demand high standards in terms of industrial technology.

In practical applications, the sensors are used right after installation, without any pre-compression process. Fortunately, in practical applications, sensors are not operated at full load, so creep is generally acceptable. In cases of full load versus non-full load, the degree of creep of the sensor is not proportional to the weight, and there is no national standard for this (the national standard applies to tests at full scale). For example: for a 10-ton sensor, when a weight of 10 tons is applied, the weight value output by the sensor changes by 2 kilograms over 30 minutes. So, when a weight of 5 tons is applied to the sensor, its output weight value will not exactly change by 1 kilogram after 30 minutes. In actual testing, it will be less than 1 kilogram. It is not a perfectly linear relationship with the applied weight.

For export purposes, reputable sensor brands with high quality include Suzhou HBM (a German brand), Sartorius (a German brand), VISHAY, and Mettler-Toledo (the most well-known in the industry). In China, Shaanxi’s AVIC Electromechanical Testing can supply sensors of different grades; it is necessary to specify this when placing an order. They have manufactured products for foreign brands before, so their process control is quite good). Among the foreign brands mentioned above, choose the one with the lower price.

OP, you’re amazing! That’s absolutely correct.

Thank you, OP; give a like. . . . . . . . . . . . . . . . . . .

Thank you for the explanation. The second stage of creep that I’m referring to should be the second phase of creep. Stable phase.

I’ve learned it!* . . . . . . . . . . . . . .

There is **no standard** for creep during the stable phase. But based on personal experience, the creep during the stable phase (after being under pressure for some time) is relatively small; generally, creep is greater at the initial stage of compression. This is also why the national standards specify creep evaluation periods of 10 seconds to half an hour, with a maximum of no more than 2 hours. I’m asking this because in your application, is the material always pressing on the sensor? The changes in data under long-term compression are not due to creep, but rather to other factors caused by several aspects.