In a concrete batching plant all of the ingredients that go into the concrete are measured by weight with special scales. These days most of them are electronic. Those scales have to be calibrated from time to time to maintain their accuracy. Calibrating is as simple as loading predetermined weights on the scales and making sure the electronic gages record that weight properly.
You Cannot Skimp on Scales When Your Concrete Needs to be Mixed Accurately
A concrete batching plant is a large-scale operation, meaning the entire facility will typically cost millions of dollars to build and maintain. With such an expense there is always the temptation to cut costs, but when it comes to your scales, you should not skimp on the resources that you allocate to this extremely important component of your entire operation. The general rule is that you pay for accuracy, and the cheaper your scale, the less accurate it is likely to be.
The majority of scales that are likely used at a concrete batching plant will have digital indicators. You will need accurate scales to measure out all the separate elements that go into making concrete – aggregate, cement, water and pigments if required. Digital scales are extremely easy to use and offer highly precise readings without some of the issues that are common with antiquated analog scales.
Ready-mixed Concrete Mixing Plant Calibration Procedure
A concrete mixing plant or concrete batching plant is widely used in concrete centralized stirring places. It is carried out according to different design and manufacturing requirements that meet the actual needs of the process so that each device with a distinct professional quality.
- Before checking, prepare enough standard weights and weigh materials.
- During the calibration process, a special operator, and their safety must be guaranteed.
- Conduct a visual inspection: measure management marks, explanatory marks, verification marks as well as taking into account safety measures, self-inspection procedures, and conditions of use.
- Set calibration of zero and peeling device accuracy.
- Conduct a bias load test.
- Conduct a weighing test.
- Conduct a Discrimination test.
- If the batching scale fails to reach the corresponding accuracy, it needs to be calibrated.
Matters Needing Attention
The batching scale calibration process should be based on the instructions, but there are a few caveats: if possible, prior to set parameters, recorded the calibration; if the calibration operation failed to read parameter settings or are if they are changed, then reset them to factory settings.
In addition, the weighing display refresh cycle is also an important parameter. For a concrete batching scale, its setting is generally in the range of 0.2 – 2. Since the setting value should not be too much, we recommended setting it between 0.2 – 0.5. You don’t want to set the cycle to longer than this as it will make the sensor response slow, thus affecting the accuracy of weighing.
Batching Plant Calibration Frequency
Calibration checks on measuring devices (scales, water meters, admixture dispensers, and moisture probes) should be performed at least once every 6 months. Some State DOTs may have a requirement for these to be performed more frequently. Documentation of these calibrations should be maintained and made available to the inspector during the plant inspection.
Also, scale accuracy should be verified anytime the plant is moved (portable plants), maintenance activities on the plant impact the weighing systems, or when there is a concern on scale accuracy determined from the batch man operating the batching process or the quality of concrete. To that end, Arlyn Scales has replacement load cells, digital weight indicators, and other scale accessories to keep your concrete batching plant fully functioning all year long.
For more information on what our team here at Arlyn Scales can do for you, use the online contact form on our website.