SoLID DAQ » Telescope Cerenkov

h1. Gas System

Basics:  The system uses a single pressure sensor (gauge monometer) linked to a controller and two solenoid valves (which are default closed).  When the pressure drops below some initial set-point (all this setpoint-1), the input valse will open and allow gas into the system.  Once the pressure reaches a second setpoint (setpoint-2) the valve will close.  A third setpoint can also be set which will open the release solenoid and allow gas out.

Current settings:  The sensor relays a signal at 1V (plus some small amount based on cable impedance) for atmospheric pressure (gauge).  Setpoint-1 will engage at 1.048, opening the input valve, at 1.056 (setpoint-2) the valve will close.  The readout on the front of the controller will display the current monometer measurement.  At Temple, the tank had a very slight leak rate, which led to an oscillation of on-off every 5 to 10 minutes.

Turning the system on/off and making changes:  The controller is itself controlled by a laptop nearby.  Turn on the controller by the switch in the back.  The login pin for the laptop is 3141 (the first 4 digits of pi).  After logining in, there is a desktop icon called "platinum".  Open this program. (Note: if the last session is running, be sure to close it out and restart the program).  You should be directed to a screen with a "Connect" button on the bottom left.  Click that to connect to the system.  Next you will see the main screen with a box on the right that has buttons that say "wait", "run", "idle", "standby","stop","pause".   The important buttons are "run" and "stop".  By clicking run, the system should engage and the readout on the screen should match what is on the front of the controller.  To stop, click "stop".

[https://redmine.jlab.org/attachments/download/938/M5461-gas-controller.pdf | Gas Controller Manual]