VICI D-4-I-SH14-R User Manual
Valco Instruments Co. Inc.
Pulsed Discharge Detector
Model D-4-I-SH14-R
Instruction Manual
Valco Instruments Co. Inc.
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d4_shim_14.P65
Rev. 5/12
Printed in USA
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Table of Contents
Introduction
Description and Operating Principles ............................................................ 1
Safety Notes and Information ........................................................................ 2
Components of the Detector System ............................................................. 3
System Requirements
Components not Included with the Detector System ..................................... 4
System Purity ................................................................................................ 4
Gas Specifications......................................................................................... 5
Installation
General Precautions...................................................................................... 6
Mounting the Detector on the GC .................................................................. 6
Gas Connections........................................................................................... 7
Pulser Module Installation .............................................................................. 9
Detector Electrical Connections ....................................................................1 0
Initial Pow er-Up .............................................................................................1 0
Capillary Column Connection ........................................................................1 2
Pac ked Column Connection ..........................................................................12
Testing for Leaks...........................................................................................13
Installing and Purging the Gas Regulator............................................... 7
Installing and Purging the Helium Purifier .............................................. 8
Connecting the Discharge Gas to the Detector....................................... 8
Mode Selection and Setup
Helium Ionization Mode.................................................................................1 4
Selective Photoionization Mode ....................................................................1 4
T roubleshooting ...................................................................................................1 6
High Background Current ..............................................................................1 6
Low Sensitivity .............................................................................................16
No Peaks......................................................................................................16
High Noise Level...........................................................................................17
Perf orming a Hydrogen Leak Test..................................................................17
Warranty .............................................................................................................1 8
Detector Perf ormance Log ...................................................................................1 9
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Introduction
Description and Operating Principle
1
The PD-D-4-I-SH14-R is a non-radioactive pulsed discharge ionization detector
(PDID) which is optimized for the Shimadzu 14 GC . A schematic representation of the basic D4 detector is shown in Figure 1.
The D4 utilizes a stable, lo w pow er, pulsed DC discharge in helium as the
ionization source. Elutants from the column, flowing counter to the flow of
helium from the discharge zone, are ionized by photons from the helium
discharge above. Resulting electrons are focused toward the collector
electrode by the two bias electrodes.
The principal mode of ionization is photoionization by radiation arising from
the transition of diatomic helium
He
1
+
(
∑
)
A
u
2
to the dissociative 2He(1S
1
)
ground state. This is the well-known Hopfield emission. The photon energy
from the He2 continuum is in the range of 13.5 eV to 17.7 eV.
The D4 is essentially non-destructive (0.01 - 0.1% ionization) and highly
sensitive. The response to organic compounds is linear ov er five orders
of magnitude with minimum detectable quantities (MDQs) in the low
picogram range. The response to fix ed gases is positiv e (the standing
current increases), with MDQs in the low ppb range.
Detector response is universal except f or neon, which has an ionization
potential of 21.56 eV. Since this potential is close to the energy of the
He* metastable (19.8 eV) but greater than the photon energy from the
He2 continuum, neon exhibits a low ionization efficiency and low detector
response.
When a dopant is added to the discharge gas, the D4 also functions
as a selective photoionization detector . (Suitable dopants include Ar for
organic compounds, Kr for unsaturated compounds , or Xe f or polyn uclear
aromatics.)
GROUND PIN
DISCHARGE REGION
HELIUM INLET
HIGH VOLTAGE
SAPPHIRE INSULATORS
BIAS ELECTRODE
CAPILLARY COLUMN
VENT
COLUMN INLET
Figure 1: Schematic of the D4 detector
COLLECTOR ELECTRODE
Introduction
2
Helium Ionization (PDHID)
The PDHID is essentially non-destructive (0.01 - 0.1% ionization) and highly
sensitive. The response to organic compounds is linear over five orders of
magnitude with minimum detectable quantities (MDQs) in the low or sub
picogram range. The response to fix ed gases is positiv e (the standing
current increases), with MDQs in the low ppb range.
The PDHID response is universal except f or neon, which has an ionization
potential of 21.56 eV. Since this potential is close to the energy of the He*
metastable (19.8 eV) but greater than the photon energy from the He
continuum, neon exhibits a low ionization efficiency and lo w detector
response.
2
Photoionization (PDPID)
Changing the discharge gas from pure helium to helium doped with argon,
krypton, or xenon changes the discharge emission profile, resulting in
resonance atomic and diatomic emissions of the rare gas added. Response
is limited to sample compounds with ionization potentials less than or equal
to the dopant gas emission energy. In this configuration, the detector is
essentially functioning as a specific photoionization detector for selective
determination of aliphatics, aromatics, and amines, as well as other species.
Since there is no lamp or window , sensitivity will not change with time.
Safety Notes and Information
CAUTION: During normal operation, the detector pr oduces ultraviolet energy (UVA, UVB), some of which may
be emitted. Do not watch the arc without e y e protection.
Symbols
HIGH VOL T A GE
V oltages presenting the risk of electric shock are present in
sever al places in the equipment. Avoid contact with hazardous live parts. Do not probe into openings or attempt to
defeat safety mechanisms .
HOT SURFACE
The surface of the detector body may be hot while in oper ation (possibly in excess of 250°C). Caution should be
observed.
A TTENTION
Refer to the manual.
PROTECTIVE EAR TH
This internal connection provides protection against electric
shock from mains voltages and should not be remov ed.
Components of the Detector System
Components of the detector system are listed in the T able 1. Chec k the
contents of the packages to verify that everything is present. Contact the
factory if anything is missing or damaged. (NOTE: damaged shipments
must remain with the original packaging for freight company inspection.)
T ab le 2 lists additional required items which must be purchased from
Shimadzu.
Table 1: Components of the D-4-I-SH14-R system
Description Quantity Product number
Detector cell, PDHID 1 PD-D4-I-RU
Pulse supply module 1 PD-M2
Instruction manual 1 MAN-PDD4-SH14
Fittings kit 1 PD-KIT-D4
Includes: 1/32" polyimide ferrule 5 ZF.5V
1/32" polyimide plug ferrule (no through hole) 1 ZF.5VX
1/16" gold-plated ferrule 5 ZF1GP
0.25 - 0.44 mm polyimide column ferrule 5 FS.4
0.4 - 0.5 mm polyimide column ferrule 5 FS.5
1/16" union, 316 SS 2 ZU1MS6
1/16" tee 1 ZT1
1/8" external to 1/16" internal adapter 2 EZR21
1/8" external to 1/16" internal reducing union 2 EZRU21
1/32" external nut 1 EN.5KN
Fused silica adapter (installed) 1 IZERA1.5
Packed column adapter 1 I-23642-D4RU
Restrictor, 30 cc/min @ 60 psi He 1 TGA-R-30F60P
Helium purifier 1 HP2
Electrometer cable assembly, Shimadzu 1 I-23230-SH14
Bias cable assembly, Shimadzu 1 I-23404-SH14
Pulser power supply 1 I-23569-I
Heater block, Shimadzu GC14 1 I-23911
Cover plate, Shimadzu GC14 1 I-23823
Introduction
3
Table 2: Components not supplied by Valco (may be obtained from Shimadzu)
Description Quantity Product number
Electrometer, FID GC14 1 221-36965-91
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