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Flammable Gas Detectors

There are four flammable gas detectors installed (one on top of the target, one each on top of the hydrogen and deuterium gas panels, one on top of the gas tanks) to provide early detection of hydrogen/deuterium leaks. These detectors are sensitive (and calibrated) over the range from 0 to 50 $\%$ Lower Explosive Limit (LEL) of hydrogen. The electro-chemical sensors were manufactured by Crowcon Detection Instruments LTD and the readout (four channels) was purchased from CEA Instruments, Inc. (The Gas Master Four System). The readout unit provides two alarm levels per channel. The low level alarm is tripped at 20 $\%$ LEL while 40 $\%$ LEL activates the high level alarm. Each channel has a relay output for both low and high level alarm states and there is also a set of common relays for both alarm levels (these common relays respond to the "logical or" of the sensor inputs). The common relays will be connected to the Fast Shut Down System, FSD, which removes the beam from the hall by disabling a grid bias at the injector.


next up previous contents
Next: Pressure Up: Flammable Gas Previous: Electrical Installation   Contents
Joe Mitchell 2000-02-29