Agilent Technologies 7820A

146
Agilent 7820 GC Service
180 °C. (See the procedure for the SS or PP in the
Maintenance manual.)
 Be sure to configure the column.
Display the signal output to determine baseline output. A stable
baseline output at any value between 0.5 and 1000 Hz
(ChemStation display units) (inclusive) is acceptable.
 If the baseline output is < 0.5 Hz, verify that the
electrometer is on. If the offset is still < 0.5 Hz, your
detector requires service.
 If the baseline output is > 1000 Hz, there may be chemical
contamination contributing to the signal. Bakeout the
uECD. If repeated cleanings do not give an acceptable
signal, check gas purity. Use higher purity gases and/or
install traps.
Create or load a method with the parameter values listed in the
table below.
Table 3. uECD Checkout Conditions
Column and sample
Type
HP-5, 30 m — 0.32 mm — 0.25 µm
(19091J-413)
Sample
µECD checkout (18713-60040 or
Japan: 5183-0379)
Column mode
Constant flow
Column pressure
6.5 mL/min (helium)
Split/splitless
inlet
Temperature
200 °C
Mode
Splitless
Purge flow
60 mL/min
Purge time
0.75 min
Purged packed
inlet
Temperature
200 °C
Detector
Temperature
300 °C
Makeup flow (N2)
30 mL/min (constant + makeup)
Baseline output
Should be < 1000 display counts
in Agilent ChemStation
(< 1000 Hz)
Oven