The purpose of the interlock system is to prevent coils from overheating. Most coils have thermistors to measure the coil temperature which is compared to a temperature setpoint. If any coil exceeds this setpoint the supplies are switched off. There is also a water flow meter (Proteus Industries 08004BN4) to monitor the water flow. If the flow drops below a certain setpoint the supplies are shut off and cannot be restarted until the flow goes back above the setpoint.
Water Flow Meters
There are three flow meters on the lattice experiment, measuring the water flowing to the Nufern amplifiers, the Transport/Fets, and the Feshbach Coils respectively.
The flow meter for the Transport/FETS is a Proteus Industries 08004BN4 which can measure 1.1 - 17 LPM flow rates. At 17LPM the voltage output is 5V. This flow meter is connected to the CATS interlock system as described above.
The flow meters for the Nufern and for the Feshbach are both Proteus Industries 08004BN1 which measure 0.4 - 5.3 LPM flow rates. The output voltage of these flow meters can be measured, but is not connected to any interlocks at the moment.
The voltage output of these flow meters can be converted to flow rates using the flow response curves in the manual
Measured Flow Rates
Flow rate for the transport system is measured using the display on the CATS. Note that the voltage read from this display is half of the voltage output by the flow meter (e.g. 0.4V is measured on CATS for a flowmeter voltage of 0.8V, indicating a flow rate of ~3LPM)
Aug 4, 2010 (using water from the wall)
- Fesbach: 0.24V
- Transport: 0.55V
- FETS: 0.29V
The setpoint was set to 0.52V. I did not record the pressure at that time…in the future make sure to record the pressure!
March 14th, 2013 (after replacing filter on transport chiller)
- Transport + FETS: 0.43V
April 2nd, 2013 (after installing new Feshbach chiller)
- Feshbach: 1.5V (was previously 1.35V using wall water)
- Nufern: 1.74V
- Transport/FETS: 0.42V