Radiometric measurement

While for nuclear limit switches and density measurements the point-to-point connection, utilizing point source and point detector is the industry standard,
continuous level measurements usually utilize at least one rod type device. As indicated earlier, rod detectors are very vulnerable against background, and therefore the potential errors caused by background are by far dominating. The sensitivity of a radiometric measurement is not automatically an indicator for the quality of the measurement. It is obvious that background and its fluctuation play a major role and error caused by background can dominate the system. Typically, it is thought that cutting activity half is having the same effect than bisecting the sensitivity.
Halving sensitivity of the detector does not change the systems overall error assuming that there is no other major source of noise like electronical noise, which can only be held up if the measurement device is developed and produced on a high standard. In fact, calculations illustrates, that the signal to noise ratio is the far better lever and this ratio is what we positively influence by managing background.  Our solution for level measurement

Similar to the nuclear limit switch, density measurements are typically point-to-point measurements, with the same error modes. For density measurements it is important to carefully manage the potential causes for systematic errors. As already explained, sophisticated temperature and aging compensations preserve the high reproducibility of the measurement itself. Also, it is imperative to establish a proper calibration, where sample taking and laboratory measurements might affect the accuracy of the calibration value. In the measurement itself the statistical error is most dominant. In real life a density measurement has high demands on accuracy and reproducibility in a very limited calibration range. Typically, the count rate ratio at the highest and lowest measured density is low and therefore the acceptable statistical error is quite small, which prohibits the use of similar count rates to a limit switch. To handle the statistical error, it helps to have a high count-rate in combination with a long time constant. Our solutions for density measurement

A level switch is a point-to-point measurement, utilizing a point source and a point detector.Systematic errors can be reduced very well, by applying good workmanship during installation and setup of the measurement. This includes establishing the system with properly calculated switching limits.
The most important and dominant error of a nuclear limit switch, is the statistical error, which is handled by statistical methods, e.g. by setting an appropriate time constant and build a reasonable mean value. Designing the system with a high enough count rate and leaving a large enough sigma difference between empty and full counts, prevent from false switching. The figure illustrates that for safe switching operations a difference of at least 6σ is recommended. Count rates leaving the 6σ band due to statistical variations occur in 0.0000001973% of all measurements – only every 16 years when applying typical detector characteristics. Our solutions for level switch measurement