Gow-Mac 580 series, Operating Manual

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Series 580 TCD Gas Chromatograph
September 2017, Rev. 5 49
NOTE: Be very careful when installing the column making sure not to have the column
end too far in that it pushes out the front of the injection port. If this happens and the
injection port nut is installed too tight, this will cause the carrier fl ow to be cut off .
This could cause damage to the detector.
CAUTION
BURN HAZARD! INJECTION PORT NUTS MAY REACH VERY HIGH
TEMPERATURES.
D. Temperature Control
The Series 580 GC can be operated at temperatures ranging from ambient to 400 °C. Operating
temperature is maintained at the injection ports, the column oven, and the detector. Temperature
controls on the injection ports, column oven, and detector are independent, solid state
proportioning type. Proportioning cycle rate is approximately 2 1/2 sec. with a total band width
of 5° C. Temperature readout and “SET” are on a 3 1/2 digit, digital meter. Selector buttons are
used to read the desired temperatures.
A centrifugal blower fan circulates and distributes the heated air, thus eliminating temperature
gradients. The blower also provides rapid cool-down when needed.
E. Column Oven
The column oven is heated by a 500 W tubular heater controlled by a proportional control. The
solid state control incorporates a platinum RTD (Resistance Temperature Detector) and a 3-3/4
turn set potentiometer. Built into the circuitry is a fail-safe feature which disables the controller’s
triac output in the event of shorted or open sensor.
The “Temperature Fail Safe” feature has independent shut down at 400 °C for injection ports and
detector. The column oven shuts down 30 °C above the column oven set point. The heating units
return to safe condition when the temperatures decrease to safe levels. The controller is easily
removed for service or replacement.
F. Detector Temperature Control
The detector is heated by two (2) 100 W heaters mounted in the DETECTOR HOUSING. The
temperature control sensor is also located in the housing.
The detector temperature is controlled in the same manner as the column oven.
It is IMPORTANT to remember that the detector is heated by fi laments as well as the heaters,
and CANNOT be operated at ambient temperature. Even with the heaters turned “OFF”, the
detector will rise in temperature to about 70 °C due to the heat from the fi laments.