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Legacy systems – Keep the source

Improve the working life of your legacy source by increasing the sensitivity of your detector

It can be concerning when your legacy radiometric system measurement point begins to drift or fail.

When instances like this happen, it can be easy to assume that the entire system needs replacement. This would include not only the costly replacement and disposal of both the source and source container but the cost of upgrading to a new detector as well.  

To alleviate this challenge, introduce technology that can ensure that your source’s life is extended. Endress+Hauser’s Gammapilot FMG50 offers a highly sensitive scintillator detector that reliably measures gamma radiation, requiring roughly an 80% lower dose rate compared to other legacy detectors such as the Geiger-Mueller detector, Ionization Chamber, or a flexible scintillation detector.

Table 1: Radiation dose rates
 * FMG50 Based on 2000mm PVT Detector

The sensitivity of a detector determines the minimum dose rate needed for a reliable gamma radiometric measurement. Since legacy detectors are not nearly as sensitive as the Gammapilot FMG50, a higher dose rate is required for accurate and valid gamma radiation measurements.  To achieve the proper dose rate levels, one of two radioactive isotopes can be selected, either cesium-137 or cobalt-60.

The selection of either isotope is based on the specific application. The most important distinctions between the two are the half-life and penetration power. Cesium-137 has a half-life of 30 years while cobalt-60 has a half-life of 5.2 years. Another important distinction is that cobalt-60 has a higher penetration power, so less activity is needed to penetrate through more material. In contrast, a higher activity level of cesium-137 would be needed to achieve the same effect. The higher the radioactive activity, the higher the dose rate.

Discover more about radiometric level measurement

Unlock the benefits that sensitive radiometric technology provides  

As legacy systems age, the performance of the system drops. This is typically the result of a combination of issues, but most notable are the effects of a lower dose rate due to the continued decay of radioactive sources or the continued degradation of the detector due to age. Previously, it was mentioned that a higher dose rate was needed for adequate measurement, so in these cases, a higher activity source must be commissioned.  Although the dose rate might not be high enough to achieve a reliable measurement with the legacy detector, using the sensitive FMG50 you can ensure the continued use of the legacy source.

Other key benefits of this radiometric technology include:
  • It is the only true loop powered radiometric transmitter.
  • It can be installed in high temperature applications up to 176°F without the need of water cooling.
  • It can help reduce maintenance costs using the Gammapilot FMG50’s advance self-monitoring, verification, and diagnostics function.
  • It is developed according to IEC 61508 for SIL2/3 applications measuring level, density, and interface.
  • A multifunctional compact transmitter for all measuring tasks: level, interface, density, concentration and point level.
  • Features automatic decay compensation which ensures accurate measurement over the entire operating life of radiation source.

Looking for further assistance?

Endress+Hauser has a dedicated team who can make the proper calculations to determine if the legacy systems source has enough radiation activity strength for continued use. We also can conduct on-site visits to make visual inspections of the source container’s integrity and survey the measurement range area to record current local dose rate readings at the detector.

For further questions regarding topics discussed in this blog, please fill the form out below to speak with one of our experts:

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