The LEM system allows to sample the liquid effluents and to perform a gross gamma measurement of the samples in Marinelli geometry. The system is designed to survey the activity released through liquid effluents, performing the calculation of volumetric activity of the samples. The system is studied to be a fixed equipment and it can be installed in several environments. LEM is a user-friendly, reliable, long-lasting and sturdy system.
From the PLC based control unit it is possible to command the sampling circuit. The system is equipped with a touch-screen operator panel. The PLC automatically manages all the cycle steps, and it constantly checks the proper functioning of the system, eventually communicating to the management software the error messages.
The LEM system saves and archives all the alarm events. The software is equipped with a routine for quality control, to be used with the test source optionally provided with the system.
LEM system is composed of the following main parts:
- Mechanical structure: stainless steel stand
- Electrical and command board with panel PC and PLC: integrated in the stand and equipped with safety switch
- Measurement system: NaI(Tl) detector, single channel analyzer PAD, 3 l Marinelli, 10 cm lead shielding well
- Sampling circuit and self-priming pump
- Software for system management, data acquisition and processing, failures and alarms indication
In addition to standard supply, the following options are available upon request:
- 137Cs source for calibration, activity < 40 kBq, composed of a gel matrix inserted in a Marinelli identical to the measurement chamber
- 137Cs point source, activity < 10 kBq, for periodical quality controls