GAMMA SWITCH
To monitor level of a liquid in a container; which is at an elevated temperature and/or under pressure and/or chemically very corrosive. A simple system which dose not require contact with container surface has been developed at BARC.
PRINCIPLE
Gamma emitting source; such as Cobalt - 60 or Cesium 137; can be enclosed in a heavy shield with a small opening in horizontal direction. This arrangement provides a beam of gamma radiation like a pencil of light produced by a torch. A gamma ray sensor such as Geiger Muller tube can detect radiation level. Under steady conditions; so long as liquid level does not interrupt the beam, the sensor will detect radiation due to attenuation in container wall only. There will be abrupt fall in the radiation level when the liquid goes above the source-detector axis. The change in the radiation level signifies that the liquid level has reached the mark represented by source-detector axis.
SPECIFICATION
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Nominal range | : | a) 10-250 counts/sec. b) 100 counts/sec (factory adj) c) Linearity better than ± 5%. |
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Hysterisis | : | 5% (factory adjusted) |
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Response time | : | 6 seconds (other value can be provided for particular application). |
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Relay contact rating | : | Two change over contacts 28 volts/1 amp resistive. |
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Ambient temp | : | -10° to +65° C storage +10° to +50° C operating. |
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Weight |
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approx. 3 Kg. |
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Detector | : | Gamma ray halogen quenched G.M. detector. |
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Source |
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Co-60 source |
APPLICATION
