Bake-Out Procedure - Thermo Scientific TRACE 1600 Hardware Manual

4
Performing Detectors Routine Maintenance
Maintaining a Thermal Conductivity Detector (TCD)

Bake-out Procedure

178 TRACE 1600/1610 Hardware Manual
The TCD detector does not usually need maintenance. Nevertheless, if you follow a few
simple precautions, you will avoid problems and prolong the detector's lifetime. Pay a special
attention to avoid contamination or damage to the filaments.
CAUTION Do not turn the filament on until the carrier gas is flowing through the
detector.
Do not shut off or disconnect the carrier gas when the detector is hot, even if the unit is
turned off.
ATTENTION N'activez pas le filament tant que le gaz vecteur ne transite pas par le
détecteur.
Veillez à ne pas couper ou débrancher le gaz vecteur quand le détecteur est chaud, même si
l'unité est hors tension.
Follow these simple rules:
• Avoid switching on the filaments when unnecessary. Doing so considerably reduces the
filament's lifetime.
• Avoid injecting samples that contain halogenated or acid compounds at high
concentrations.
• Ensure that oxygen (air) cannot enter into the filament's cells. Oxidation will irreversibly
damage the filaments. Install traps for moisture and oxygen on the gas lines to reduce the
risk of contamination.
• Turn off the filament before disconnecting the column from the detector. When the
column is disconnected, air will enter into the cell and the filament, if powered on, will be
damaged.
• Turn on the filament only if the column is connected. It is a good practice to let the gas
flow through the cells for 5-10 minutes before powering the filaments.
See Bake-out Procedure,
for additional information.
Under normal conditions, the TCD requires no routine maintenance. However, if the
detector is exposed to chemicals which may condense or polymerize within the detector and
adversely affect performance, an attempt of filament cleaning could be baked out at high
temperatures (up to 300°C). Inert carrier gas flow should be maintained during the
reconditioning procedure.
Filament temperature should also be increased to approximate the setpoint of the bake-out
temperature.
If a 24-hour bake-out is not sufficient to remove the contamination, the unit must be
returned to the factory for disassembly and cleaning.
Measuring the Carrier Gas Flow Rate, and Shutting Down the TCD
Thermo Scientific