Connecting the Cooling Gas LineConnecting the Cooling Gas Line
The Cooling Gas fitting, a fitting on the rear of the cabinet, marked with a 830 kPa gauge (120 psig) warning label, can used with either the Finned Air Cooling System (FACS), Refrigerated Cooling System (RCS), or Liquid Nitrogen Cooling System (LNCS). Follow the directions below appropriate to the type of cooler you are using.
Pressurized air is used in conjunction with the Finned Air Cooling System
for the DSC instrument. Air
cooling can be initiated automatically at the end of an experiment to
facilitate cool down. (Select the Post
Test function for this operation.) Use the following steps to install
the cooling gas line.
Locate the Cooling Gas fitting (see the figure to the right) on the rear of the cabinet, marked with a 830 kPa gauge (120 psig) warning label.
Make sure your compressed lab air source is regulated to between 170 to 830 kPa gauge (25 to 120 psig) and is free of oil and water vapors.
Connect a compressed lab air line to the Cooling Gas fitting.
CAUTION: The Cooling Gas line feeds into a pressure-regulated valve that is set to 274 kPa (25 psig). The source pressure setting should not go below this value.
NOTE: Nitrogen may also be used as a cooling gas.
The RCS Purge, which is connected to the Cooling Gas fitting, is used to automatically purge the interior of the RCS cooling head when the cell is open during loading/unloading samples under Autosampler control and during cell conditioning. Follow the instructions below to connect the line for the RCS purge.
Locate the Cooling Gas port on the right rear of the instrument. The RCS Purge will be connected to that port.
Make sure that the pressure of your gas source for the RCS Purge is also regulated to 140 kPa gauge (20 psig). Dry nitrogen should be used.
NOTE: Since both the Base Purge and RCS Purge will be exposed to temperatures below ambient, the gases used should be moisture-free. Nitrogen gas of 99.999% purity is recommended.
Use 1/4-inch O.D. tubing to connect the gas source to the Cooling Gas port for the RCS Purge. TeflonŽ TFE tubing with Swagelock fittings is recommended. A solenoid valve automatically regulated by the Advantage Q Series™ software determines when the RCS Purge is on. An orifice in the instrument automatically regulates the flow rate.
The LNCS Purge, which is connected to the Cooling Gas fitting, is used to automatically purge the interior of the LNCS cooling head when the cell is open during loading/unloading samples under Autosampler control and during cell conditioning. Follow the instructions below to connect the line for the LNCS purge.
Locate the Cooling Gas port on the right rear of the instrument. The LNCS Purge will be connected to that port.
Make sure that the pressure of your gas source for the LNCS Purge is also regulated to 140 kPa gauge (20 psig). Dry nitrogen should be used.
NOTE: Since both the Base Purge and LNCS Purge could be exposed to temperatures below ambient, the gases used should be moisture-free. Nitrogen gas of 99.999% purity is recommended.
Use 1/4-inch O.D. tubing to connect the gas source to the Cooling Gas port for the LNCS Purge. TeflonŽ TFE tubing is recommended. A solenoid valve automatically regulated by the Advantage Q Series™ software determines when the LNCS Purge is on. An orifice in the instrument automatically regulates the flow rate.
