The following work was completed today on the EHD water leak sensors:

• Mike Vogel installed a 1/4" copper tube which leads from the east side of the EHDT shielding down to the catch tray below the water blocks.  This can be used for future testing of the in-tray sensors without removing the shield blocks.  It may also be possible to test the other sensors if enough water is poured into the tray for it to overflow and eventually get them wet.  The routing of the copper tube is not expected to interfere with the vertical shield plug
• Ray Mendoza re-located the SMT circuit boards to a rack on the north wall of the E-Hall, east of the concrete shield wall.  The push-connect terminal on one board was damaged, so there is currently no electronics installed for EHD:LEAK06  (After various debugging over the last couple weeks it was eventually determined that the previous problems with these sensors was caused by a shared power source for the relays and the sensors themselves.  Ray installed a dedicated 9V power supply for the sensors, with 24V supply to the relays still coming from the PLC)
• We swapped the wiring of two of the sensors so that LEAK01 and LEKA02 are the strips located in the tray as specified in interlock spec Document-112445 (see below for details of final installation)
  • Inside tray east side sensor is cable #4, wired to EHD:LEAK01
  • Inside tray west side sensor is cable #2, wired to EHD:LEAK02
  • Outside tray east side sensor is cable #3, wired to EHD:LEAK03
  • Outside tray west side sensor is cable #1, wired to EHD:LEAK04
• After the wiring was completed we shorted across each sensor in the junction box near the beam dump.  EHD:LEAK01 through LEAK05 responded as expected

• Water was poured into the 1/4" copper tube to test the sensor strips in the tray.  After approximately 50mL sensor #2 triggered, and #1 triggered after approximately 100mL total.  Both sensors were still in alarm 5 minutes later.

• Water was applied to sensor #3 (outside tray, east side) using a snake camera with plastic tube attached.  Approximately 50mL was applied;  The sensor triggered once after a small amount of water reached the strip, came out of alarm, then went back into alarm when more water was applied.  It stayed in alarm for approximately 1 minute then cleared

• EHD:LEAK04 (outside tray west side) was triggered by pouring water onto the ground in the general area of the sensor (direct application with the snake camera was not possible). 125mL was initially poured which did not trigger the sensor.  An additional 125mL was applied which triggered it.  More water was added to the LEAK03 sensor to confirm that the system behaves properly with all 4 sensors in alarm

•  Air was forced down towards the sensors using a shop-vac hooked up in reverse.  LEAK03 and LEAK04 cleared within a couple minutes.  LEAK01 and LEAK02 cleared in approximately 2 hours.