Measuring instruments are widely used in manufacturing process. These instruments are classified according to the basic physical property they measure. Instrument error is an unavoidable problem from measuring process. Let’s take a look at how these errors occurred and how can we minimise them. There are four main reasons that these errors occurred:
- Wrong Measuring method;
- Measuringinstrument is badly calibrated;
- There are interference sources in the measuring process;
Some of these reasons are from the instrument itself and the others are from external factors.
- Errors from the instrument
The mechanical properties or electrical structure of the instrument is not perfectly designed and assembled can often cause the error of the instrument itself. For example, errors will be occurred if the instrument is not carefully calibrated before use or instrument has been stay unused for long time without recalibration. The only way to eliminate these errors is to make sure manufacturer and operator check calibration of the instrument to make sure they are in great working condition before use.
- Errorsfrom the installation
At installation stage, the instrument should be installed in strict accordance with the instruction book. However, errors often occur due to improper installation method adopted by operator in process. For example, the spectrophotometer should be preheated for half an hour before use. If it is not preheated, it may lead to the occurrence of errors. To avoid these errors, operators need to strictly follow the installation and user instruction or consult with people with knowledge on the instrument before install and use.
- Man-made errors
Man-made errors are normally occurred from improper operation. For example, take wrong data readings or use wrong method when measuring will lead to incorrect data collection hence affect product quality. Such errors can be easily avoided by provide training and set strict requirement or rules during operation.
- Errors caused by External factors
External factors are big contributors to occurrence of reading errors. The influence of surrounding environment on the measuring result is obvious. This occurred easily with high-precision instruments. Factors such as changes in temperature, humidity, electric field, magnetic field, or electromagnetic waves. Different instrument has different weakness under different environment as well. For example, ultrasonic flow meter can be badly affected under serious acoustic interference environment. To avoid these, a good understanding of the instrument on operation and follow instruction is the perfect solution.
In conclusion, it is important to choose most reliable and appropriate instrument for specific application to minimise errors. In some cases, seeking advices from instrument manufacturer on specific application is very useful and can save a lot of time. In addition, provide training and implement strict rules during production process are also great ways to avoid errors.