VICI D-2-IM - Manual (Page 20)

16
Installation
Initial Power-Up
1. If it is not already there, set the MODE switch on the front of the controller to
PDHID.
2. Set the discharge gas flow as specified in on page 14 in the section entitled
“Connecting the Discharge Gas to the Detector”.
CAUTION: Always make sure that discharge gas is flowing
before powering up the detector.
3. Apply power to the helium purifier.
4. Turn on the MAINS switch located on the back of the controller.
5. Set the detector temperature to 100°C with the TEMPERATURE control knob.
Allow time for the detector and helium purifier to reach temperature.
6. Turn on the DISCHARGE switch, located on the front of the controller. The
discharge should start within five minutes. (Once a system has been up and
running, the discharge will start within a few seconds.)
In a clean system, the discharge will have a peach/pink color. A purple discharge
indicates impurities and/or leaks in the discharge gas stream.
7. Check the detector standing/background current, indicated in the LED DISPLAY
on the controller, and record it in the Detector Performance Log on the last page
of this manual. The optimum detector background current is 0.5 to 1.5 nA. The
initial value may be higher, but as the detector bakes out at its operating
temperature, the background current should decrease to the optimum value.
8. The recommended detector temperature is 20°C above the column tempera-
ture, with a minimum of 100°C. Set the detector to the operating temperature
required for the intended analysis. When the detector has reached the set
temperature, read and record the standing current.
9. Install the column as described on page 14, leaving the oven at ambient
temperature. Start carrier flow, then read and record the standing current.
The difference between this reading and the one previous is the ionization of
the combined impurities in and eluting with the carrier gas. The smaller the
difference, the better the quality of the gas exiting the column.
10. Set the column oven to the temperature required for the intended analysis.
When the oven reaches the set temperature, read and record the standing
current.
The difference from the previous reading is the ionization of the column
bleed. The smaller the difference, the better the column is conditioned.
NOTE: Some stationary phases will have a higher bleed than others, but
are still suitable for this detector. However, the lower the bleed, the lower
the chances of contaminating the detector cell.