Xcalibur, ChromQuest, and Accela are registered trademarks of Thermo Fisher Scientific Inc. in the United
States.
LightPipe is a trademark of Thermo Fisher Scientific Inc in the United States.
PEEK is a trademark of Victrex PLC.
The following are registered trademarks in the United States and other countries: Windows is a registered
trademark of Microsoft Corporation. Teflon is a registered trademark of E. I. du Pont de Nemours and
Company.
Thermo Fisher Scientific Inc. provides this document to its customers with a product purchase to use in the
product operation. This document is copyright protected and any reproduction of the whole or any part of this
document is strictly prohibited, except with the written authorization of Thermo Fisher Scientific Inc.
The contents of this document are subject to change without notice. All technical information in this
document is for reference purposes only. System configurations and specifications in this document supersede
all previous information received by the purchaser.
Thermo Fisher Scientific Inc. makes no representations that this document is complete, accurate or errorfree and assumes no responsibility and will not be liable for any errors, omissions, damage or loss that might
result from any use of this document, even if the information in the document is followed properly.
This document is not part of any sales contract between Thermo Fisher Scientific Inc. and a purchaser. This
document shall in no way govern or modify any Terms and Conditions of Sale, which Terms and Conditions of
Sale shall govern all conflicting information between the two documents.
Software versions: Xcalibur 2.1 and higher data system or ChromQuest 4.2 and higher data system
Hardware version: Accela PDA Detector (80 Hz version)
Revision history: Revision A, August 2009
For Research Use Only. Not for use in diagnostic procedures.
Page 3
Regulatory Compliance
Thermo Fisher Scientific performs complete testing and evaluation of its products to ensure full compliance with
applicable domestic and international regulations. When the system is delivered to you, it meets all pertinent
electromagnetic compatibility (EMC) and safety standards as described in the next section or sections by product name.
Changes that you make to your system might void compliance with one or more of these EMC and safety standards.
Changes to your system include replacing a part or adding components, options, or peripherals not specifically
authorized and qualified by Thermo Fisher Scientific. To ensure continued compliance with EMC and safety standards,
replacement parts and additional components, options, and peripherals must be ordered from Thermo Fisher Scientific
or one of its authorized representatives.
Accela PDA Detector (80 Hz version)
EMC Directive 2004/108/EC
EMC compliance has been evaluated by TUV Rheinland of North America, Inc.
EN 61326-12006EN 61000-4-32006
EN 550112007, A2: 2007EN 61000-4-4 2004
EN 61000-3-22006EN 61000-4-52005
EN 61000-3-31995, A1: 2001, A2: 2005EN 61000-4-62007
EN 61000-4-21995, A1: 1999, A2: 2001EN 61000-4-112001
FCC Class A, CFR 47 Part 15: 2007
Low Voltage Safety Compliance
Low Voltage Safety Compliance has been evaluated by TUV Rheinland of North America, Inc.
This device complies with Low Voltage Directive 2006/95/EC and harmonized standard EN 61010-1:2001,
IEC 61010-1:2002, UL 61010 A-1:2004, CAN/CSA 22.2 61010-1:2004.
Page 4
FCC Compliance Statement
THIS DEVICE COMPLIES WITH PART 15 OF THE FCC RULES. OPERATION IS SUBJECT TO
THE FOLLOWING TWO CONDITIONS: (1) THIS DEVICE MAY NOT CAUSE HARMFUL
INTERFERENCE, AND (2) THIS DEVICE MUST ACCEPT ANY INTERFERENCE RECEIVED,
INCLUDING INTERFERENCE THAT MAY CAUSE UNDESIRED OPERATION.
CAUTION Read and understand the various precautionary notes, signs, and symbols contained inside
this manual pertaining to the safe use and operation of this product before using the device.
Notice on Lifting and Handling of
Thermo Scientific Instruments
For your safety, and in compliance with international regulations, the physical handling of this Thermo Fisher Scientific
instrument requires a team effort to lift and/or move the instrument. This instrument is too heavy and/or bulky for one
person alone to handle safely.
Notice on the Proper Use of
Thermo Scientific Instruments
In compliance with international regulations: Use of this instrument in a manner not specified by Thermo Fisher
Scientific could impair any protection provided by the instrument.
Notice on the Susceptibility
to Electromagnetic Transmissions
Your instrument is designed to work in a controlled electromagnetic environment. Do not use radio frequency
transmitters, such as mobile phones, in close proximity to the instrument.
For manufacturing location, see the label on the instrument.
Page 5
WEEE Compliance
This product is required to comply with the European Union’s Waste Electrical & Electronic Equipment (WEEE)
Directive 2002/96/EC. It is marked with the following symbol:
Thermo Fisher Scientific has contracted with one or more recycling or disposal companies in each European Union
(EU) Member State, and these companies should dispose of or recycle this product. See www.thermo.com/
WEEERoHS for further information on Thermo Fisher Scientific’s compliance with these Directives and the
recyclers in your country.
WEEE Konformität
Dieses Produkt muss die EU Waste Electrical & Electronic Equipment (WEEE) Richtlinie 2002/96/EC erfüllen.
Das Produkt ist durch folgendes Symbol gekennzeichnet:
Thermo Fisher Scientific hat Vereinbarungen mit Verwertungs-/Entsorgungsfirmen in allen EU-Mitgliedsstaaten
getroffen, damit dieses Produkt durch diese Firmen wiederverwertet oder entsorgt werden kann. Mehr Information
über die Einhaltung dieser Anweisungen durch Thermo Fisher Scientific, über die Verwerter, und weitere Hinweise,
die nützlich sind, um die Produkte zu identifizieren, die unter diese RoHS Anweisung fallen, finden sie unter
www.thermo.com/WEEERoHS
.
Page 6
Conformité DEEE
Ce produit doit être conforme à la directive européenne (2002/96/EC) des Déchets d'Equipements Electriques et
Electroniques (DEEE). Il est marqué par le symbole suivant:
Thermo Fisher Scientific s'est associé avec une ou plusieurs compagnies de recyclage dans chaque état membre de
l’union européenne et ce produit devrait être collecté ou recyclé par celles-ci. Davantage d'informations sur la
conformité de Thermo Fisher Scientific à ces directives, les recycleurs dans votre pays et les informations sur les
produits Thermo Fisher Scientific qui peuvent aider la détection des substances sujettes à la directive RoHS sont
disponibles sur www.thermo.com/WEEERoHS
high voltages that can cause personal
injury. Before servicing, shut down the
instrument and disconnect the instrument
from line power. Keep the top cover on
while operating the instrument. Do not
remove protective covers from PCBs.
Chemical: This instrument might contain
hazardous chemicals. Wear gloves when
handling toxic, carcinogenic, mutagenic,
or corrosive or irritant chemicals. Use
approved containers and proper
procedures to dispose waste oil.
Heat: Before servicing the instrument,
allow any heated components to cool.
Fire: Use care when operating the system
in the presence of flammable gases.
Eye Hazard: Eye damage could occur
from splattered chemicals or flying
particles. Wear safety glasses when
handling chemicals or servicing the
instrument.
General Hazard: A hazard is present that
is not included in the above categories.
Also, this symbol appears on the
instrument to refer the user to instructions
in this manual.
When the safety of a procedure is
questionable, contact your local Technical
Support organization for Thermo Fisher
Scientific San Jose Products.
Elektroschock: In diesem Gerät werden
Hochspannungen verwendet, die
Verletzungen verursachen können. Vor
Wartungsarbeiten muß das Gerät
abgeschaltet und vom Netz getrennt
werden. Betreiben Sie Wartungsarbeiten
nicht mit abgenommenem Deckel. Nehmen
Sie die Schutzabdeckung von Leiterplatten
nicht ab.
Chemikalien: Dieses Gerät kann
gefährliche Chemikalien enthalten. Tragen
Sie Schutzhandschuhe beim Umgang mit
toxischen, karzinogenen, mutagenen oder
ätzenden/reizenden Chemikalien.
Entsorgen Sie verbrauchtes Öl
entsprechend den Vorschriften in den
vorgeschriebenen Behältern.
Hitze: Warten Sie erhitzte Komponenten
erst nachdem diese sich abgekühlt haben.
Feuer: Beachten Sie die einschlägigen
VorsichtsmaBnahmen, wenn Sie das
System in Gegenwart von entzündbaren
Gasen betreiben.
Verletzungsgefahr der Augen:
Verspritzte Chemikalien oder kleine
Partikel können Augenverletzungen
verursachen. Tragen Sie beim Umgang mit
Chemikalien oder bei der Wartung des
Gerätes eine Schutzbrille.
Allgemeine Gefahr: Es besteht eine
weitere Gefahr, die nicht in den
vorstehenden Kategorien beschrieben ist.
Dieses Symbol wird im Handbuch
auBerdem dazu verwendet, um den
Benutzer auf Anweisungen hinzuweisen.
Wenn Sie sich über die Sicherheit eines
Verfahrens im unklaren sind, setzen Sie
sich, bevor Sie fortfahren, mit Ihrer
lokalen technischen
Unterstützungsorganisation für Thermo
Fisher Scientific San Jose Produkte in
Verbindung.
Choc électrique: L’instrument utilise des
tensions capables d’infliger des blessures
corporelles. L’instrument doit être arrêté et
débranché de la source de courant avant
tout intervention. Ne pas utiliser
l’instrument sans son couvercle. Ne pas
enlever les étuis protecteurs des cartes de
circuits imprimés.
Chimique: Des produits chimiques
dangereux peuvent se trouver dans
l’instrument. Portez des gants pour
manipuler tous produits chimiques
toxiques, cancérigènes, mutagènes, ou
corrosifs/irritants. Utiliser des récipients
et des procédures homologuées pour se
débarrasser des déchets d’huile.
Haute Temperature: Permettre aux
composants chauffés de refroidir avant
tout intervention.
Incendie: Agir avec précaution lors de
l’utilisation du système en présence de
gaz inflammables.
Danger pour les yeux: Des projections
chimiques, liquides, ou solides peuvent
être dangereuses pour les yeux. Porter des
lunettes de protection lors de toute
manipulation de produit chimique ou pour
toute intervention sur l’instrument.
Danger général: Indique la présence
d’un risque n’appartenant pas aux
catégories citées plus haut. Ce symbole
figure également sur l’instrument pour
renvoyer l’utilisateur aux instructions du
présent manuel.
Si la sûreté d’une procédure est
incertaine, avant de continuer, contacter
le plus proche Service Clientèle pour les
produits de Thermo Fisher Scientific San
Jose.
Descarga eléctrica: Este instrumento
utiliza altas tensiones, capaces de
producir lesiones personales. Antes de
dar servicio de mantenimiento al
instrumento, éste debera apagarse y
desconectarse de la línea de alimentacion
eléctrica. No opere el instrumento sin sus
cubiertas exteriores quitadas. No remueva
las cubiertas protectoras de las tarjetas
de circuito impreso.
Química: El instrumento puede contener
productos quimicos peligrosos. Utilice
guantes al manejar productos quimicos
tóxicos, carcinogenos, mutagenos o
corrosivos/irritantes. Utilice recipientes y
procedimientos aprobados para
deshacerse del aceite usado.
Altas temperaturas: Permita que lop
componentes se enfríen, ante de efectuar
servicio de mantenimiento.
Fuego:
Tenga cuidado al operar el
sistema en presencia de gases
inflamables.
Peligro par los ojos: Las salicaduras de
productos químicos o particulas que
salten bruscamente pueden causar
lesiones en los ojos. Utilice anteojos
protectores al mnipular productos
químicos o al darle servicio de
mantenimiento al instrumento.
Peligro general: Significa que existe un
peligro no incluido en las categorias
anteriores. Este simbolo también se utiliza
en el instrumento par referir al usuario a
las instrucciones contenidas en este
manual.
Cuando la certidumbre acerca de un
procedimiento sea dudosa, antes de
proseguir, pongase en contacto con la
Oficina de Asistencia Tecnica local para
los productos de Thermo Fisher Scientific
San Jose.
Shock da folgorazione. L’apparecchio è
alimentato da corrente ad alta tensione
che puo provocare lesioni fisiche. Prima di
effettuare qualsiasi intervento di
manutenzione occorre spegnere ed isolare
l’apparecchio dalla linea elettrica. Non
attivare lo strumento senza lo schermo
superiore. Non togliere i coperchi a
protezione dalle schede di circuito
stampato (PCB).
Prodotti chimici. Possibile presenza di
sostanze chimiche pericolose
nell’apparecchio. Indossare dei guanti per
maneggiare prodotti chimici tossici,
cancerogeni, mutageni, o
corrosivi/irritanti. Utilizzare contenitori
aprovo e seguire la procedura indicata per
lo smaltimento dei residui di olio.
Calore. Attendere che i componenti
riscaldati si raffreddino prima di
effetturare l’intervento di manutenzione.
Incendio. Adottare le dovute precauzioni
quando si usa il sistema in presenza di gas
infiammabili.
Pericolo per la vista. Gli schizzi di
prodotti chimici o delle particelle presenti
nell’aria potrebbero causare danni alla
vista. Indossare occhiali protettivi quando
si maneggiano prodotti chimici o si
effettuano interventi di manutenzione
sull’apparecchio.
Pericolo generico. Pericolo non
compreso tra le precedenti categorie.
Questo simbolo è utilizzato inoltre
sull’apparecchio per segnalare all’utente
di consultare le istruzioni descritte nel
presente manuale.
Quando e in dubbio la misura di sicurezza
per una procedura, prima di continuare, si
prega di mettersi in contatto con il
Servizio di Assistenza Tecnica locale per i
prodotti di Thermo Fisher Scientific San
Jose.
Page 8
CAUTION SymbolCAUTION
Electric Shock: This instrument uses
high voltages that can cause personal
injury. Before servicing, shut down the
instrument and disconnect the instrument
from line power. Keep the top cover on
while operating the instrument. Do not
remove protective covers from PCBs.
Chemical: This instrument might contain
hazardous chemicals. Wear gloves when
handling toxic, carcinogenic, mutagenic,
or corrosive or irritant chemicals. Use
approved containers and proper
procedures to dispose waste oil.
Heat: Before servicing the instrument,
allow any heated components to cool.
Fire: Use care when operating the system
in the presence of flammable gases.
Eye Hazard: Eye damage could occur
from splattered chemicals or flying
particles. Wear safety glasses when
handling chemicals or servicing the
instrument.
General Hazard: A hazard is present that
is not included in the above categories.
Also, this symbol appears on the
instrument to refer the user to instructions
in this manual.
When the safety of a procedure is
questionable, contact your local Technical
Support organization for Thermo Fisher
Scientific San Jose Products.
The LightPipe flowcell contains optical fibers that are exposed at both ends of the cell. When
you handle the LightPipe flowcell, take care to avoid touching the exposed optical fibers. The
following photo contains a view of the exposed optical fibers at the inlet end of the LightPipe
flowcell.
Drainage Connections
Before you start the solvent flow from the pump, make sure that the solvent flow from the
outlet end of the LightPipe flowcell is connected to the drainage system.
Y To make the drainage connections
1. Insert the outlet tubing from the PDA detector into the autosampler drain manifold (see
Hot Surface, UV Radiation, and High Voltage Hazards
Electric shock caution
UV radiation caution
Hot surface caution
Before you pull the PDA detector’s chassis partially out of the housing to replace the
deuterium or tungsten lamp assemblies, do the following in order:
1. Turn off the lamps.
2. Wait approximately 30 minutes for the lamp cover to cool to room temperature.
3. Turn off the PDA detector, and then unplug the power cord from line power.
After you pull the PDA detector’s chassis partially out of the housing, you can see the heat,
UV radiation, and electrical shock caution labels inside the lamp compartment.
Turning off the lamps and waiting approximately 30 minutes for the lamp cover to cool to
room temperature removes the hot surface hazard. Unplugging the PDA detector from line
power removes the UV radiation and hazards.
Before you attempt to pull the lamp cover out of the PDA detector, lightly touch the cover to
make sure that it is not hot.
To obtain optimal performance from your LC system and to prevent personal injury or an
environment hazard, do the following:
• Keep good records.
• Read the manufacturers’ Material Safety Data Sheets (MSDSs) for the chemicals being
used in your laboratory.
• Remove particulate matter from your samples before you inject them into the liquid
chromatograph.
• Use HPLC-grade solvents.
• Connect the drainage tubes from the pump, autosampler, and detector to an appropriate
waste receptacle. Dispose of solvents as specified by local regulations.
Keep Good Records
To help identify and isolate problems with either your equipment or your methodology,
Thermo Fisher Scientific recommends that you keep good records of all system conditions, for
example,% RSDs on retention times and peak areas, peak shape, and resolution. At a
minimum, keep a chromatogram of a typical sample and standard mixture, well documented
with system conditions, for future reference. Careful comparison of retention times, peak
shapes, peak sensitivity, and baseline noise can provide valuable clues to identifying and
solving future problems.
Chemical Toxicity
Although the large volume of toxic and flammable solvents used and stored in laboratories can
be quite dangerous, do not ignore the potential hazards posed by your samples. Take special
care to read and follow all precautions that ensure proper ventilation, storage, handling, and
disposal of both solvents and samples. Become familiar with the toxicity data and potential
hazards associated with all chemicals by referring to the manufacturers’ Material Safety Data
Sheets.
Sample Preparation
Always consider the solubility of your sample in the solvent/mobile phase. Sample
precipitation can plug the column, tubing, or LightPipe flowcell causing flow restriction. This
obstruction can result in irreparable damage to the system. You can avoid particulate matter
by filtering the samples through 0.45 or 0.2 micron (or less) filters.
Many chemical manufacturers provide a line of high-purity or HPLC-grade reagents that are
free of chemical impurities. Routine filtration of all solvents or eluents through a 0.45 or
0.2 micron (or less) fluorocarbon filter before placing them in the solvent reservoir
significantly prolongs the life and effectiveness of the inlet filters, check valves and seals,
injector, and column. Typically, HPLC-grade solvents do not require filtration.
Choose a mobile phase that is compatible with the sample and column that you have selected
for your separation. Remember that some solvents can corrode stainless steel.
Solvent Disposal
Make sure you have a solvent waste container or other kind of drain system available at or
below the benchtop level. Most solvents have special disposal requirements and should not be
disposed of directly down a drain. Follow all governmental regulations when disposing of any
chemical.
High-pressure Systems and Leaks
LC systems operate at high pressures. Because liquids are not highly compressible they do not
store much energy. Accordingly, there is little immediate danger from the high pressures in an
LC system. However, if a leak occurs, correct it as soon as possible. Always wear eye and skin
protection when operating or maintaining an LC system. Always shut down the system and
return it to atmospheric pressure before attempting any maintenance.
The detector is a full-featured, time-programmable, photodiode array (PDA) detector capable
of scanning the ultraviolet-visible wavelength range from 190 to 800 nm. You can acquire
data across the entire spectral range (with an effective resolution of 1.2 nm) at a rate of 0.5 to
80 Hz with 20-bit digital conversion.
The PDA detector is a benchtop unit for inclusion in the Accela liquid chromatography
system. You control the detector through an Ethernet link to a data system computer that has
the Xcalibur™ or ChromQuest™ data system installed. The detector consists of a dual-light
source, an optical bench, a photodiode array, a low voltage power supply, several printed
circuit boards (PCBs), and four status light-emitting diodes (LEDs).
Figure 2 shows the optical system used in the detector. The dual-light source includes a
deuterium lamp for detection in the ultraviolet wavelength range (190 to 360 nm) and a
tungsten-halogen lamp for detection in the visible wavelength range (360 to 800 nm). The
light output from the two lamps overlaps in the 300 to 500 nm range. You can increase or
decrease the light intensity reaching the photodiode array by manually adjusting the
attenuator for the deuterium lamp and the attenuator for the tungsten lamp.
The optical bench contains a beam combiner, focusing lens, filter wheel, LightPipe flowcell,
beam shaper, folding mirror, and grating. The beam combiner reflects the light coming from
the tungsten-halogen lamp so that it is parallel to and coincident with the light from the
deuterium lamp. A lens focuses the combined beam on the inlet window of the LightPipe
flowcell through the filter wheel. The standard filter wheel has two positions. For normal
operation, leave the filter wheel in Position 1 (Open). Position 2 contains a sealed quartz
cuvette filled with a holmium oxide/perchloric acid solution (traceable to NIST) used for
wavelength accuracy verification and calibration.
The light focused on the inlet window of the LightPipe flowcell travels down the cell, is
partially absorbed by the sample flowing through the cell, and exits into the beam shaper. The
beam shaper is a fiber bundle. Its entrance aperture is circular to collect light from the
LightPipe flowcell. The other end of the bundle is arranged to produce a narrow “slit” of light
for the grating. The beam shaper transfers all the light to the grating for greater light
throughput than the mechanical slit used in conventional photodiode array detectors.
The folding mirror between the output of the beam shaper and the grating shortens the
optical bench, reducing the physical size of the detector. The grating disperses the light beam
onto the 512-element photodiode array (two of the diodes in this array are not used). Because
the spectrum of light falling on the array is 611 nm (190 to 800 nm, inclusive), the effective
spacing of the diodes is 611 nm / 510 = 1.2 nm. Firmware on the CPU PCB automatically
interpolates diode intervals to arrive at integer wavelengths.
The photodiode array is mounted on the Array Acquisition PCB, which also contains all the
analog detection circuitry. The PDA detector continuously scans the diode array at 20-, 40-,
or 80-Hz (user selectable), converts the light intensity at each diode into a 20-bit digital word,
and then stores these words in a dual-port Random Access Memory (RAM) on its CPU PCB.
The CPU reads the data, processes the data based on the user parameters, and sends the
processed data to the data system computer.
LightPipe Flowcell
The Accela PDA Detector ships with a 10 mm or 50 mm LightPipe flowcell.
The internal bore of the 10 mm LightPipe flowcell is 10 mm long and has a volume of 2 μL.
The internal bore of the 50 mm LightPipe flowcell is 50 mm long and has a volume of 10 μL.
A special, low refractive index coating of the internal bore ensures a high optical throughput
and minimizes short-term noise.
The mobile phase enters the 10 mm LightPipe flowcell through a port in the bottom
of the LightPipe flowcell and exits through a port in the front of the LightPipe flowcell
(see Figure 3). Directing the flow upward helps prevent air bubble entrapment.
Sensitive optical fibers are exposed at both ends of the LightPipe flowcell (see Figure 4).
Thermo Fisher Scientific ships the LightPipe flowcell with end caps to protect these optical
fibers (see Figure 5). Do not remove the protective end caps until you install the LightPipe
flowcell. Replace the protective end caps for storage if you remove the LightPipe flowcell from
the detector.
CAUTION Do not touch the ends of the LightPipe flowcell. Touching the ends of the
flowcell can damage the exposed optical fibers. If you must grasp the ends of the LightPipe
flowcell, wear clean, talc-free gloves.
Figure 4. End of the LightPipe flowcell
Figure 5. LightPipe flowcell with protective end caps
The Accela PDA Detector has two lamps. The tungsten-halogen lamp emits light in the
visible region, and the deuterium lamp emits light in the ultraviolet region. With use, the
deuterium lamp emits less and less light before it fails to ignite (see Figure 6). In contrast, the
light output from the tungsten-halogen lamp remains relatively constant until the lamp fails.
Figure 6. Deuterium lamp intensity versus lamp usage hours
1
Introduction
Lamp Lifetime and Detector Noise
Detector noise is inversely proportional to the amount of light that reaches the diode array
and the sampling time for the photodiodes of the diode array. Decreasing the amount of light
that reaches the diode array and decreasing the sampling time both increase the detector noise
level.
These topics provide guidance on minimizing detector noise and maximizing the useful lamp
lifetime:
• Controlling the Amount of Light that Reaches the Diode Array
• Selecting an Appropriate Diode Array Scan Rate
Controlling the Amount of Light that Reaches the Diode Array
During a fixed sampling period, the amount of light reaching the diode array is proportional
to the light output from the lamp and the aperture of the manual attenuators (partially open
to completely open).
To compensate for the decreased light output caused by lamp aging, increase the aperture of
the PDA detector’s attenuators (see “Completing the Installation and Verifying Operation” on
Note At the 20 Hz diode array scan rate, you can compensate for the decreased light
output from the deuterium lamp by increasing the attenuator aperture throughout the
lamp’s lifetime of approximately 2000 hours.
Page 26
1
Introduction
Lamp Lifetime and Detector Noise
Selecting an Appropriate Diode Array Scan Rate
When you configure the PDA detector, you have three options for the diode array scan rate:
20, 40, and 80 Hz. The diode array scan rate is the rate at which the PDA detector samples
the integrated intensity of the diodes.
IMPORTANT For validated HPLC methods, record the appropriate configuration setting
for the diode array scan rate. The diode array scan rate affects the detector noise level.
The option you select affects the detector noise level, the useful lifetime of the deuterium
lamp, and the available sampling rates in the data system method.
Note For information on creating methods to control the PDA detector, refer to the data
system Help.
As you increase the diode array scan rate, the sampling time per diode decreases. To achieve
the same integrated light intensity, you must increase the light throughput to the diode array
by opening the detector’s attenuators (“Completing the Installation and Verifying Operation”
on page 25). As the lamp ages, it emits less and less light (see Figure 6). So again, to achieve
the same light throughput to the diode array, you must increase the attenuator aperture.
Eventually, the attenuator aperture reaches a physical limit. When you can no longer increase
the attenuator aperture, the integrated light intensity begins to decrease, and detector noise
level begins to increase. The attenuator aperture reaches this physical limit sooner at the
higher diode array scan rates.
The useful lifetime of the lamp depends on the acceptable noise level for your application. At
the 20 Hz diode array scan rate, you can compensate for the decreased light output from the
deuterium lamp by increasing the attenuator aperture throughout the lamp’s lifetime of
approximately 2000 hours.
To maximize the useful lifetime of the deuterium lamp, select a diode array scan rate that is
appropriate for your application:
• For standard chromatography applications, select the 20 Hz diode array scan rate. With
this selection, you can acquire up to 20 data points per second per chromatogram and
optimize integration for chromatographic peaks with baseline widths as narrow as
1second.
• For most fast chromatography applications, use the default selection of 40 Hz. With this
selection, you can acquire up to 40 data points per second per chromatogram and
optimize integration for chromatographic peaks with baseline widths as narrow as
0.5 seconds.
• For fast chromatography applications that have chromatographic peaks with baseline
widths of less than 0.5 seconds, select the 80 Hz diode array scan rate.
Four status LEDs labeled Power, Communication, Run, and Lamps are located on the left
door of the detector (see Figure 7). Ta b le 1 lists the status LEDs and their meaning.
Figure 7. Accela PDA Detector status LEDs
Table 1.Status LEDs and meanings
LEDStateMeaning
Power GreenThe detector is turned and has downloaded the
operational file.
AmberThe detector is turned on but has not yet downloaded the
operational file from the data system computer.
Comm GreenCommunication to the data system PC has been
established.
AmberThere is no communication with the data system.
Run GreenThe detector is ready for a run.
Flashing greenA run is in progress and the detector is sending data to the
data system computer.
AmberThe PDA detector is not ready to start a run for one of
these reasons:
• A valid method has not been downloaded (following
power on).
• Both lamps are off, or one of the lamps is failing to
turn on.
• The lamp or wavelength calibration is not valid.
Flashing amberThe PDA detector is in an error state while in the
Run mode.
Lamps GreenOne or both lamps are turned on.
AmberThe lamps are off or the D2 lamp is starting. The
D2 lamp takes approximately 30 seconds to turn on.
Diode array scan rate20, 40, or 80 Hz (user selectable)
*
:
≤ 6 μAU/cm (at 254 nm with a 50 mm LightPipe, a 1 mL/min flow rate (MeOH),
20 Hz diode array scan rate, 5 Hz data rate, 5 nm bandwidth, and 2 second rise time)
Rise time: 0.0, 0.02, 0.05, 0.1, 0.2, 0.5, 1, 2, 5, or 10 s (user selectable)
Cell dimensions: 10 mm LightPipe flowcell or 50 mm LightPipe flowcell
Cell pressure rating: 1000 psi
Diodes: 512
Diode spacing: 1.2 nm
Light source: Deuterium and tungsten-halogen lamps, pre-aligned
Filter wheels: Standard filter wheel: two-position wheel, one open position and one Holmium
oxide/perchloric acid-filled cuvette, NIST traceable. Optional linearity verification
wheel: five-position wheel, one with perchloric acid blank and four cuvettes with
different concentrations of potassium dichromate in perchloric acid, NIST traceable
Analog outputs (2): 20-bit digital/analog conversion, three outputs/channel scaled to 10 mV/AU,
100 mV/AU, or 1.0 V/AU
Remote controls: Start, Zero
Dimensions: 18 cm (7.1 in.) × 36 cm (14.2 in.) × 47 cm (18.5 in.) (h × w × d)
Weight: 19.5 kg (43 lbs)
Power requirements: 100/115 or 230 V ac; 50/60 Hz, 200 VA max
Operating temperature: +10 to +30 °C
Storage temperature: - 40 to +70 °C
Operating humidity: 5% to 95% non-condensing relative humidity
Product certification: CE, TUV-C/US, FCC (EMI)
*
According to ASTM E1657-98 “Standard Practice for Testing Variable-Wavelength Photometric Detectors Used in Liquid Chromatography”
This chapter describes the initial installation of the PDA detector, including the connections
to other chromatographic instrumentation. The installation checklist, on the back of this
page, is an abbreviated version of this chapter that you can use as a quick reference for
conducting a successful installation. Make a copy of the checklist, fill it out when the
installation is complete, and include it in your maintenance records.
Contents
• Installation Checklist
• Unpacking and Inspecting the Instrument
• Making Initial Instrument Preparations
• Making the Back Panel Connections
• Installing the LightPipe Flowcell
• Connecting the Remote Outputs
• Turning On the Detector for the First Time
• Completing the Installation and Verifying Operation
Carefully remove the detector from the shipping container and inspect both the detector and
the packaging for any signs of damage. If you find any damage, save the shipping materials
and immediately contact the shipping company.
Check the shipping container for the Accela PDA Detector, a LightPipe Flowcell Kit, a power
cable, and an accessory kit that contains the following items:
•Two signal cables
• One RJ12 serial communications cable
• One Ethernet communications cable
• One RJ45 9-pin adapter
Ensure that you have received all the items listed on the packing list. If any items are missing,
contact your Thermo Fisher Scientific representative immediately.
2
Installation
Unpacking and Inspecting the Instrument
The part numbers of the accessory kit items are listed in Ta b l e 1 1 on page 104.
Making Initial Instrument Preparations
Place the PDA detector on a benchtop as close as possible to the chromatographic column
outlet (minimizing the length of tubing necessary for connection to the LightPipe flowcell
inlet). Be sure to place the detector in a draft-free location away from an open window, air
conditioner vents, or other circulating air source. A stable room temperature is necessary for
applications requiring maximum detection sensitivity. Allow at least 15 cm (6 in.) of clear
space between the back panel of the detector and any wall or obstruction. This clear space
provides access to the back-panel connectors and a free flow of cooling air.
You must have the following tools for installation:
Use the cables provided in the Accela system accessory kit to make the connections to the back
panel of the detector. The part numbers for these cables are listed in Tab l e 8 on page 103.
For instructions on connecting the PDA detector to line power, see “Turning On the Detector
for the First Time” on page 24.
This section contains the following topics:
• Connecting the Ethernet Cable
• Connecting the System Interconnect Cable
• Connecting the Analog Outputs
• Setting the Analog Output Voltage
• Setting the Unit ID
Connecting the Ethernet Cable
Y To connect the Ethernet communication cable
• Connect the Ethernet switch to the Ethernet connector port of the PDA detector using
the supplied CAT5, 7 ft. long, shielded Ethernet cable with ferrite clamp.
• Connect the Ethernet switch to the data system computer using the supplied CAT5, 7 ft.
long, shielded Ethernet cable with ferrite clamp.
Connecting the System Interconnect Cable
The system interconnect cable coordinates the timing of the Accela modules during an
injection sequence. There are two versions of this cable. The previous version of the cable,
which you might have in your laboratory, contains five connectors labeled DET, M/S, A/S,
LC PUMP, and MS PUMP. The new version of the interconnect cable, shown in Figure 8,
contains three detector connectors labeled DETECTOR, two pump connectors labeled
PUMP, an autosampler connector, and an MS detector connector.
Y To connect the system interconnect cable
1. Plug one of the connectors labeled DETECTOR into the left, 8-pin receptacle labeled
pins 1 through 8 on the back panel of the detector (see Figure 9).
2. Plug one of the connectors labeled PUMP into the 8-pin receptacle on the back panel of
the Accela Pump.
3. Plug the autosampler connector (identified by the A/S tag on its adjacent cable) into the
left, 8-pin receptacle on the back panel of the Accela Autosampler.
The installation kit provides two analog signal cables (twin-axial computer cables) to connect
the analog outputs from the PDA detector to other data collection devices.
The analog signal cables have three wires protruding from the ends of the shielded cable. Two
of these wires are electrically insulated and carry an analog signal to data collection devices.
Typically, the wire with the clear insulation is connected to the positive analog output, and the
wire with the black insulation is connected to the signal ground (sometimes referred to as the
negative signal). The third wire is not insulated and grounds the cable shielding. The cable
shielding reduces signal noise caused by radio frequency interference and is most effective if
the bare wire is grounded at just one end.
The ends (1/4 in.) of the analog signal wires are stripped and soldered to allow electrical
contact and to prevent fraying.
On the detector’s back panel, there are two analog output channels with three different analog
voltage outputs per channel: CHA – 10 mV, CHA – 100 mV, CHA – 1 V, CHB – 10 mV,
CHB – 100 mV, CHB – 1 V; and a single ground per channel: GND A and GND B. Select
the appropriate output voltage for your data collection system.
Y To make each electrical connection
1. Insert the end of the wire into the appropriate terminal in the 8-pin terminal connector.
Hold the wire in place while you tighten the small terminal set screw firmly onto the wire.
2. Insert the terminal connector into the 8-pin analog connector numbered 9 through 16 at
the back of the instrument (see Figure 10).
Figure 10. Analog signal connectors
IMPORTANT Do not connect the detector ground terminals to any earth ground on
your data system computer. Doing so leads to an increased noise level and a
subsequent decrease in sensitivity.
You control the analog outputs from the data system by selecting the acquisition wavelengths,
bandwidth, rise time, and zero functions of the detector. These outputs are compatible with
data collection systems using any of the three different voltages (10mV, 100mV, or 1V) by
selecting the appropriate terminal of the analog output terminal connector (Figure 10).
Setting the Unit ID
The Accela PDA Detector ships with the unit ID preset using the two rotary switches located
on the back panel. Figure 11 shows the rotary switches preset to a value of 01. The range of
values for the unit ID is 01 to 99. The value of 00 is reserved for special service functions.
The unit ID must correspond with the stack ID specified in the Instrument Configuration
application. Do not change the unit ID setting for your detector unless you are controlling
more than one PDA detector from one computer. For details on configuring your detector,
see Chapter 3, “Configuration.”
2
Installation
Making the Back Panel Connections
Use a small flathead screwdriver to change the setting of the rotary switches.
Figure 11. Unit ID rotary switches set to a value of 01
Making Remote Communications Connections
The Accela PDA Detector has the remote communications inputs RUN and ZERO, and the
remote communications output EVENT (see Figure 12).
The RUN input receives an inject signal from the autosampler. The system interconnect cable
connects the RUN input to the signal from the autosampler.
ZERO
Use the ZERO connection on the back panel of the detector to zero the detector signal output
from a remote device (generally at the start or end of each sample run).
You can remotely zero the Accela PDA Detector with either a TTL low signal or with a
contact closure.
The system interconnect cable connects the ZERO input to the signal from the autosampler.
Tip When the Accela PDA Detector is part of an Accela LC system, connect the system
interconnect cable to these terminals (see “Connecting the System Interconnect Cable” on
page 12).
EVENT
Use the EVENT output connection to trigger an external device such as a fraction collector.
Set up the parameters for this signal in the instrument control method created in the Xcalibur
or ChromQuest data system.
If you use a TTL signal to trigger the external device, connect the PDA EVENT terminal
(pin 8) to the positive pin on the external device input, and connect one of the PDA GND
terminals (either pin 1 or 7) to the external device negative pin. The Accela PDA Detector has
open collector outputs that require a pull-up resistor (typically 10 kΩ) when connecting to
TTL inputs.
Note The external device input terminal might not have markings indicating positive and
negative polarity. In this case, connect the PDA EVENT terminal to one of the pins, and
connect a PDA GND terminal to the other pin.
If you trigger the external device by contact closure, connect the PDA +5 V output (pin 2) to
the positive input terminal of the external device, and connect the PDA EVENT output
(pin 8) to the negative input terminal of the external device.
The LightPipe flowcell is packed in a small, separate box within the detector shipping carton.
This small box contains the LightPipe flowcell (with a protective cap on each end) and a
plastic bag containing the inlet and outlet tubing and fingertight fittings. The part numbers
for these items are listed in Ta bl e 6 on page 103.
CAUTION Use only PEEK fittings to connect tubing to the flowcell. The appropriate
PEEK fittings are included in the LightPipe Flowcell Accessory Kit.
Y To install the LightPipe flowcell
1. Open the front doors of the detector.
2. Unscrew the captive screw that secures the LightPipe flowcell access cover to the front
panel of the detector and pull the cover off (see Figure 13).
3. Unscrew the retaining block knob and remove the retaining block (see Figure 14).
Figure 14. View of the retaining block and the retaining block knob
4. Remove the protective end caps from the ends of the LightPipe flowcell.
5. Connect the inlet port of the LightPipe flowcell:
a.Use the PEEK fitting included with the LightPipe Flowcell Kit to connect one end of
the red 0.005 in. ID, insulated inlet tubing to the flowcell inlet port. Slide the
protective insulating sleeve of the tubing as close as possible to the inlet port of the
LightPipe flowcell.
Note The insulating sleeve of the inlet tubing minimizes temperature
fluctuations, which cause baseline drift.
b.Connect the other end of the tubing to the LC column outlet.
6. Connect the outlet port of the LightPipe flowcell:
• If you are not connecting to an MS detector, use a PEEK fitting to connect the blue
0.010 in. ID, outlet tubing to the LightPipe flowcell outlet. Place the other end of the
outlet tubing into the waste reservoir. When you use an optional backpressure
regulator (see Ta b l e 7 on page 103), connect the outlet line to the low-pressure union
and waste tubing.
• If you are connecting the LightPipe flowcell outlet to an MS detector, use the PEEK
fittings to connect one end of the red 0.005 in. ID, PEEK tubing (included in the
MS detector accessory kit) to the outlet port of the LightPipe flowcell and to connect
the other end of the tubing to the inlet port of the MS detector.
IMPORTANT If you have several detectors (fluorescence, refractive index,
electrochemical, and so on) hooked up in a series, place your Accela PDA
Detector closest to the column outlet. The LightPipe flowcell in the Accela PDA
Detector can withstand the greatest backpressure.
Tip For best results, when you run the system at a low backpressure, use a
backpressure regulator to prevent bubble formation in the PDA detector’s
LightPipe flowcell.
7. Position the slot located on the top of the LightPipe flowcell under the retaining bolt in
the detector, and then slide the LightPipe flowcell into place.
The location of the outlet fitting depends on the size of the LightPipe flowcell:
• Place the 10 mm LightPipe flowcell so that the inlet fitting is on the bottom-left side,
and the outlet fitting is on the front side (see Figure 15).
• Place the 50 mm LightPipe flowcell so that the inlet fitting is on the bottom-left side
and the outlet fitting on the top-right side (see Figure 16).
Figure 15. Location of the inlet and outlet tubing for the 10 mm LightPipe flowcell
8. Replace the LightPipe flowcell retaining block.
9. Reinstall and hand tighten the retaining block bolt knob (see Figure 16).
Figure 16. Inlet and outlet tubing connections for the 50 mm LightPipe flowcell
10. Replace the flowcell access cover, ensuring that the inlet and outlet tubing pass through
the slots (see Figure 13 on page 17) without being pinched. Tighten the captive screw to
secure the flowcell access cover to the detector.
The Accela PDA Detector has two remote outputs: READY and EVENT (see Figure 10 on
page 14). The outputs are open collectors and are each capable of sinking < 30 mA at
30 V dc, suitable for connecting to TTL and other families of ICs. In addition, there is a 5 V
output that supplies +5 V dc at 150 mA maximum that you can use for testing digital input
signals. When connecting to TTL inputs, a pull-up resistor (typically 10 kΩ) is required
across the +5 V output and the open collector input connection if one is not built into the
external device.
The polarity settings (active high or active low) of these outputs must match those of the
inputs of connecting equipment.
Setting the Remote Output Polarities from the Xcalibur Data System
Y To set the polarity of the remote outputs
1. Install the Xcalibur data system if you have not already done so.
2
Installation
2. Add the Accela PDA Detector to the configuration for your instrument. See Chapter 3,
“Configuration.”
3. Start the Xcalibur data system.
4. In the Xcalibur Roadmap view, click the Instrument Setup icon.
The Instrument Setup window appears.
5. In the view bar, click the Accela PDA button.
The Instrument Setup view for the Accela PDA Detector appears.
6. On the menu bar, choose Accela PDA > Direct Control.
The Accela PDA Direct Control dialog box appears.
Note The Accela Autosampler requires low active remote inputs.
1. Place the power switch at the front of the unit in the Off position (released or out
position).
2. Ensure that the PDA detector is properly connected to the data system computer.
3. Ensure that the data system lists the appropriate configuration settings for the PDA
detector.
For information on instrument configuration, see Chapter 3, “Configuration.”
4. Check the fuse size (see “Replacing the Fuses” on page 95).
You can operate the PDA detector at 100/115V or 230V. However, you must ensure that
the appropriate fuses are installed (see Figure 19 and Ta b l e 2 ).
Figure 19. View of the power supply module and the power line label
USE ONLY WITH
250 V FUSES
DISCONNECT POWER
BEFORE REPLACING FUSES
Table 2.Fuses
Line power voltageFuse size
100/115VT3.15 A
230VT1.6 A
5. Attach the power cord to the power entry module on the back panel of the PDA detector
and connect it to the power source.
6. Turn the power on by pushing the power button in to engage it.
The Power LED turns amber as it downloads the operational file, and then turns solid
green. If it does not light at all, see Chapter 7, “Troubleshooting.”
Completing the Installation and Verifying Operation
STANDARD FILTER WHEEL
1 : OPEN
2 : HOLMIUM OXIDE FILTER
1
Tungsten
attenuator tab
Deuterium
attenuator tab
Two-position filter wheel
with holmium oxide
Completing the Installation and Verifying Operation
The Accela PDA Detector is calibrated at the factory. During installation, a Thermo Fisher
Scientific field service engineer adjusts the light throughput and recalibrates the detector.
The PDA detector uses the holmium oxide spectrum to verify its wavelength accuracy.
A two-position filter wheel (see Figure 20) that is accessible from the front panel of the PDA
detector contains this calibration solution.
For optimal performance, recalibrate the PDA detector and adjust its attenuators as part of a
routine maintenance program and whenever you move the instrument, replace the LightPipe
flowcell, or replace a lamp.
Because the deuterium lamp emits less light with use, monitor the integrated light intensity of
the diodes as part of a routine maintenance program, and adjust the attenuators when you
notice an increase in baseline noise. Because the diode array scan rate affects the integrated
light intensity, you must also adjust the attenuators when you modify the PDA detector’s
configuration by changing the diode array scan rate (see Chapter 3, “Configuration,” on
page 9).
2
Installation
The tabs that control the position of the attenuators are located on the front panel of the PDA
detector (see Figure 20). To adjust the light throughput, you push the attenuator tabs up or
down as you view the light intensity from your data system. Pushing the left tab up or down
controls the light throughput from the deuterium (D2) lamp. Pushing the right tab up or
down controls the light throughput from the tungsten-halogen (W) lamp.
The only manual controls on the Accela PDA Detector are the On/Off switch below the
left-front door of the unit and the manual attenuators and holmium oxide wheel that you
access from the front panel; otherwise the chromatography data systems controls all other
instrument control functions.
To control the detector, you must add it to the instrument configuration for your data system
and specify its stack ID and diode array scan rate. You set the unit ID is set by adjusting the
two rotary switches on the back panel of the detector. The switches are set to 01 at the factory
(see Figure 21). Do not adjust the switches unless you are controlling more than one Accela
PDA Detector from the same data system computer.
Figure 21. Unit ID set to 01
The diode array scan rate is the unfiltered rate at which the PDA detector samples the light
intensities for the diode array. You can set the Accela PDA Detector (80 Hz version) to scan
the array at a 20, 40, or 80 Hz sampling rate.
To control the PDA detector from the Xcalibur data system, add it to the configured devices
list in Thermo Foundation, and then specify its stack number and diode array scan rate.
Y To configure your instrument in Thermo Foundation
1. Open the Instrument Configuration application.
For Xcalibur 2.1 or higher, from the computer desktop, choose Start > All Programs > Thermo Foundation 1.0 > Instrument Configuration.
The Thermo Foundation Instrument Configuration window appears (see Figure 22).
Figure 22. Thermo Foundation Instrument Configuration window
2. In the Available Devices list, double-click each of your Accela devices.
As you double-click a device in the Available Devices list, it appears in the list of
configured devices.
6. Depending on the current configuration of the instrument, do one of the following:
• If you are adding the Accela PDA Detector to a current configuration for your Accela
LC stack, leave the selection in the Instrument type list as Accela.
• If you want to erase the configuration for a previously configured Accela LC stack,
select Accela in the Instrument type list and click OK in the message dialog box that
appears.
• If you want to change the instrument type to Accela, select Accela in the Instrument
type list and click OK in the message dialog box that appears.
7. Click Configure.
The Accela dialog box appears.
8. In the Available modules pane, double-click the Detector button.
The Analog icon appears in the Configured modules pane.
9. To add the PDA detector to the instrument configuration:
a.Double-click the Analog button.
The Detector Configuration dialog box appears (see Figure 25).
Figure 25. Detector Configuration dialog box
b.In the Detector Name box, type a name to identify the Accela PDA Detector.
When you open the Instrument window, this name appears in the Analysis Channel
list.
c.In the Detector Model list, select PDA.
d.In the Acquisition Source list, select PDA Plus ACQ.
e.Leave the Y-Axis units set to the default of mAU and the Y-Axis Multiplier set to the
default of 0.001.
f.Click .
The Accela PDA Configuration dialog box appears (see Figure 26).
This chapter describes how to use the diagnostics to check the operation of the PDA detector,
calibrate the detector, and view the event log.
To perform diagnostics from the Xcalibur data system, ensure that your detector is connected
to the data system computer, configured as part of an instrument in the data system, and
turned on. For information on adding the PDA detector to the Xcalibur instrument
configuration, see “Thermo Foundation Instrument Configuration” on page 28.
If you move the PDA detector, replace lamps, install a new flowcell, or change the configured
diode array scan rate for the detector, the system performance can change. With use, the
deuterium lamp produces less and less light so that the system performance changes as the
lamp’s lifetime hours increase.
To verify the proper operation of the PDA detector, follow these procedures:
1. “Monitoring Lamp Performance from the Xcalibur Data System” on page 38
2. “Adjusting the Light Throughput with the Xcalibur Data System” on page 42
3. “Calibrating the PDA Detector from the Xcalibur Data System” on page 44
IMPORTANT Before calibrating the PDA detector, make sure that the diode array is not
saturated.
Contents
• Opening the Accela PDA Direct Control Dialog Box
• Controlling the Lamps from the Xcalibur Data System
• Monitoring Lamp Performance from the Xcalibur Data System
• Adjusting the Light Throughput with the Xcalibur Data System
• Calibrating the PDA Detector from the Xcalibur Data System
• Retrieving, Viewing, Printing, and Clearing the Event Log
Controlling the Lamps from the Xcalibur Data System
Controlling the Lamps from the Xcalibur Data System
As lamps age, they emit less light, which results in increased baseline noise. If the noise level
on your detector signal is unacceptable, and cleaning the LightPipe flowcell does not help, use
the diagnostic features of the software to determine the cause of the problem. If light output
becomes too low and adjusting the attenuators as described in “Adjusting the Light
Throughput with the Xcalibur Data System” on page 42 does not help, replace the lamps.
The detector keeps track of the number of hours each lamp has been operating. The
deuterium lamp has a lifetime of approximately 2000 hours and the tungsten lamp has a
lifetime of approximately 2500 hours. Lamp lifetime varies depending on the application (see
“Lamp Lifetime and Detector Noise” on page 5).
Turning On the Lamps
Y To turn on the lamps
1. Open the Accela PDA Direct Control dialog box (see “Opening the Accela PDA Direct
Control Dialog Box” on page 34).
2. Click the Configuration tab.
The Configuration page appears (see Figure 28).
Figure 28. Configuration page of the Accela PDA Direct Control dialog box
Controlling the Lamps from the Xcalibur Data System
3. Click Tu rn On for the associated lamp.
When you turn on the deuterium lamp, its Status readback reads Starting during the
30-second ignition period, and then it changes to On. If there is a problem with either
lamp, its Status readback reads Failed.
Note The intensity of the deuterium lamp falls off very slightly over a period of time
after the lamp is turned on. Plan to wait at least one hour for the lamp to stabilize
after a cold start before collecting data in the spectral range of the deuterium lamp.
Resetting the Lamp Lifetime
Y To reset the displayed lamp lifetime
1. Open the Accela PDA Direct Control dialog box (see “Opening the Accela PDA Direct
Control Dialog Box” on page 34).
2. Click the Configuration tab.
The Configuration page appears (see Figure 28 on page 35).
3. Click Reset Lifetime for the associated lamp.
The stored total run time for the associated lamp resets to zero, and the Last Lifetime
Reset readback is updated to the current date and time.
Note Avoid indiscriminately clicking the Reset buttons. Click Reset only after you
replace the associated lamp with a new one.
Setting the Startup Time for the Lamps
Y To set the startup time for the lamps
1. Open the Accela PDA Direct Control dialog box (see “Opening the Accela PDA Direct
Control Dialog Box” on page 34).
2. Click the Configuration tab.
The Configuration page appears (see Figure 28 on page 35).
3. In the Programmed Lamp Startup area of the Configuration page, click Change.
Controlling the Lamps from the Xcalibur Data System
The Lamp Start Up Time dialog box appears (see Figure 29).
Figure 29. Lamp Startup Time dialog box
4. To change the time, click in the Xcalibur should start the lamps at box. Then use the
keyboard arrow keys, the number keys, or both to change the time.
Tip If you inadvertently click the Xcalibur should start the lamps at box more than
once to make a new entry, close the dialog box, and then reopen it. This time take
care to use only the keyboard arrow keys and number keys to enter a time value.
5. Click OK to apply the new lamp startup time.
Use the Programmed Start option to pre-warm the lamps before starting a sequence of sample
analyses.
Monitoring Lamp Performance from the Xcalibur Data System
Monitoring Lamp Performance from the Xcalibur Data System
With use, the deuterium lamp emits less and less light. To monitor the performance of the
PDA detector’s lamps, follow these procedures:
1. “Preparing the PDA Detector to Monitor Lamp Performance,” on this page
2. “Creating a Display Method to View Light Intensity,” on this page
3. “Viewing an Intensity Scan” on page 40
Preparing the PDA Detector to Monitor Lamp Performance
Y To prepare the PDA detector to monitor lamp performance
1. Open the Accela PDA Direct Control dialog box (see “Opening the Accela PDA Direct
Control Dialog Box” on page 34).
2. Make sure that the lamps are on and equilibrated:
a.Click the Configuration tab.
The Configuration page appears (see Figure 28 on page 35).
b.Check the status and usage of each lamp.
c.If they are not already on, turn on both the deuterium (D2) and tungsten (W) lamps.
d.Wait one hour for both lamps to equilibrate.
Creating a Display Method to View Light Intensity
To adjust the attenuators and monitor the status of the lamps, create a display method. You
cannot use a display method to acquire sample data.
Intensity display methods have a .spda file extension. The data system’s auditing feature does
not track the creation and modification of intensity display methods.
Y To create a display method
1. Open the Accela PDA Method page:
a.In the Xcalibur Roadmap view, click the Instrument Setup button.
The Instrument Setup view appears.
b.In the view bar, click the Accela PDA button.
The Accela PDA Instrument Setup view appears with the Accela PDA Method page
displayed.
b.In the Accela PDA Diode/Intensity Warning dialog box, click Ye s.
The Save Accela PDA Display Method dialog box appears.
c.In the File name box, type a file name.
d.Click Save.
The data system saves the file with an .spda file extension.
Viewing an Intensity Scan
Y To view an intensity scan
1. From the menu bar of the Accela PDA view in the Instrument Setup window, choose
Accela PDA > Direct Control.
The Accela PDA Direct Control dialog box appears.
2. Click the Display tab.
Note The .spda file extension is a special file extension used for all method files
based on Diode/Intensity units. These methods cannot be used in the Sequence
Setup portion of Xcalibur. You can only load files with the .spda extension in the
Direct Control dialog box. They are not tracked by the data system’s auditing
feature.
The Display page appears (see Figure 32 on page 41).
Monitoring Lamp Performance from the Xcalibur Data System
4. Browse to the display method. Then click Open to load the method.
The file name of the display method (.spda) appears in the box above the Spectrum plot.
5. To start the data stream, click Start Data (see Figure 32).
The Spectrum and Channels plots begin to update and the Start Data button changes to
the Snapshot button.
6. Press ALT+PRINT SCREEN to save a picture of the scan to the Clipboard. Paste this
picture into a text editor such as Microsoft Word. Keep this scan for future comparisons
to see if there is degradation in light intensity. Date the printout and add it to your
maintenance records.
Adjusting the Light Throughput with the Xcalibur Data System
Adjusting the Light Throughput with the Xcalibur Data System
The first time that you adjust the attenuators, you must create a display method. After you
create the method for adjusting the attenuators, save it with a name that you can associate
with adjusting the attenuators and store it for future use.
Decreasing light throughput increases baseline noise. Increasing light throughput can saturate
the diode array. When the array is saturated, the response from the PDA detector is a flat
baseline.
During the deuterium lamp’s lifetime of approximately 2000 hours (see “Lamp Lifetime and
Detector Noise” on page 5), the lamp’s light output decreases. Adjust the attenuators as the
light output from the deuterium lamp decreases and whenever you do the following:
• Replace either lamp (see “Replacing the Lamps” on page 89)
• Replace the LightPipe flowcell (see “Installing the LightPipe Flowcell” on page 17)
• Change the configured diode array scan rate (see “Thermo Foundation Instrument
Configuration” on page 28)
Tip The integrated light intensity viewed on the Display page is a function of the light
throughput to the diode array and diode array scan rate. When you change the diode array
scan rate, you must adjust the light throughput.
• If you increase the diode array scan rate (for example, from 20 Hz to 80 Hz), you
must increase the light throughput to achieve the same intensity counts.
• If you reduce the diode array scan rate (for example, from 80 Hz to 20 Hz), check the
intensity counts, and if necessary reduce the light throughput to avoid saturating the
array.
Adjusting the position of the attenuator tabs changes the light throughput to the diode
array: up increases and down decreases the light throughput to the diode array (see
Figure 20 on page 25).
Y To adjust the attenuators while viewing the light intensities
1. Prepare the PDA detector to monitor an intensity scan (see “Preparing the PDA Detector
to Monitor Lamp Performance” on page 38)
2. If you have not already done so, create a display method that scans from diode 2 to diode
511 with a diode step of 1 and that displays the default discrete channel wavelengths
(see “Creating a Display Method to View Light Intensity” on page 38).
Adjusting the Light Throughput with the Xcalibur Data System
3. Load the display method to the detector, and click Start Data. (see “Viewing an Intensity
Scan” on page 40).
The spectrum of light intensities appears in the top window.
For the UV region, the diode of maximum intensity is between diode 10 and diode 40.
For the Visible region, the diode of maximum intensity is between diode 400 and
diode 500. Ignore the spike at approximately diode number 380. This spike is an
emission line of the deuterium lamp.
4. Adjust the left attenuator tab (UV attenuation) to achieve a Channel A value as close as
possible to 900000 intensity counts without saturating the array.
IMPORTANT With a new deuterium lamp, when you select the 20 Hz option for the
diode array scan rate, you can typically adjust the intensity to an optimum value of
900000 to 950000 counts. If you adjust the intensity too high, you can saturate the
array. So take care to avoid saturating the array.
5. Adjust the right attenuator tab (Visible attenuation) to achieve a Channel C value as close
as possible to 900000 intensity counts without saturating the array.
6. After you finish adjusting the attenuators, close the front doors of the detector.
Calibrating the PDA Detector from the Xcalibur Data System
Calibrating the PDA Detector from the Xcalibur Data System
To calibrate the PDA detector from the Xcalibur data system, follow these procedures:
• Performing a Dark Current Calibration from the Xcalibur Data System
• Performing a Wavelength Calibration from the Xcalibur Data System
Performing a Dark Current Calibration from the Xcalibur Data System
The Array calibration measures and corrects for the dark current produced by the diodes of
the photodiode array. The dark current is the small amount of background signal that is
produced by the diodes of the array even when both lamps are turned off. Typical dark current
values range from 2000 to 4000 counts.
The environmental conditions of your laboratory can cause the dark current of the diode
array to increase over time. For best results, perform an array calibration (dark current) after
any of the following events occurs:
• After 100 hours of use or monthly, whichever comes first
• Whenever a significant temperature change occurs
•After you move the detector
• After you replace the lamp
• After you update the firmware by placing a new firmware file in the data system directory
Because the dark current produced by the diodes rises as the temperature within the detector
rises, warm up the lamps for one hour before you perform a dark current calibration.
Warming up the lamps for one hour equilibrates the detector to its normal operating
temperature.
The PDA detector briefly turns the lamps off as it performs the dark current calibration
routine. After it completes the dark current calibration, the PDA detector turns the lamps
back on.
Y To perform the dark current calibration from the Xcalibur data system
1. Pump methanol through the flowcell at 1 mL/min.
2. Turn on both lamps and wait one hour for the lamps to equilibrate (see “Controlling the
Lamps from the Xcalibur Data System” on page 35). Leave the Accela PDA Direct
Calibrating the PDA Detector from the Xcalibur Data System
10. Click Finish.
The detector stores the calibration results. The date and time of the calibration appears
in the Dark Current Calibration area of the Calibration page following Last Calibration
(see Figure 39).
Figure 39. Calibration page with dark current calibration results
Calibrating the PDA Detector from the Xcalibur Data System
Performing a Wavelength Calibration from the Xcalibur Data System
The alignment of the spectrum on the diode array depends on the physical alignment of
various components of the optical bench. The alignment can become offset if the detector is
sharply jolted in shipping, for example. Such bumps and jars can slightly change the
wavelength of light reaching the photodiode array. Use the automated wavelength calibration
to determine wavelength accuracy and to correct for any misalignment.
Y To perform a wavelength calibration from the Xcalibur data system
1. Pump HPLC-grade methanol at 1 mL/min through the flowcell.
2. Turn on both lamps and wait one hour for the lamps to equilibrate (see “Controlling the
Lamps from the Xcalibur Data System” on page 35).
3. After the detector has reached a stable temperature (approximately one hour after you
turn on the lamps), proceed with the calibration:
a.In the Accela PDA Direct Control dialog box, click the Calibration tab
The Calibration page appears (see Figure 40).
Figure 40. Calibration page of the Accela PDA Direct Control dialog box
Calibrating the PDA Detector from the Xcalibur Data System
b.In the Wavelength Calibration area, click Calibrate.
The preconditions page of the wavelength calibration wizard appears (see Figure 41).
Figure 41. Preconditions page
c.Read the preconditions, and determine if they have been met:
• If the preconditions have been met, click Next to proceed with the calibration.
• If the preconditions have not been met, click Cancel to close the wizard and
prepare the PDA detector for calibration.
Note You can click Cancel on any page of the Wavelength Calibration
wizard to stop the calibration process.
4. On page 2 of the wavelength calibration wizard (see Figure 42), do the following:
a.Select a peak set from the list.
The peak set should span the wavelengths you use under normal operating
conditions. Figure 42 shows the selection of the Holmium Oxide 5 peak set. The
detector uses this wavelength list to perform the wavelength calibration.
Note Xcalibur has four calibration files to choose from. For example, the
Holmium Oxide UV file contains five wavelengths in the UV region while the
other files use sets of wavelengths from both the UV and Visible wavelength
regions. The holmium oxide absorbance maxima are selected from a spectrum
published in “Holmium Oxide Solution Wavelength Standard from 240 to
640 nm - SRM 2034 (NIST Special Publication 260-54).”
Figure 48. Page 8 of the Wavelength Calibration wizard
4
Xcalibur Diagnostics for the PDA Detector
Calibrating the PDA Detector from the Xcalibur Data System
11. Check that the delta values are within ±1 nm, and then do one of the following:
• If the Delta values are acceptable, proceed to step 12.
• If the delta values are not within the range of ±1 nm, do not export the results, and
proceed to step 13. Complete the calibration procedure, and then repeat the
wavelength calibration. If, after applying a second calibration, the Delta values are
still not within the range of ±1 nm, call your Thermo Fisher Scientific service
representative for assistance.
12. (Optional) Print a report of the calibration results:
a.Click Export Results to print the results to a file.
13. On page 8 of the Wavelength Calibration wizard (see Figure 48 on page 55), click Apply.
The final page of the Wavelength Calibration wizard appears (see Figure 51).
Figure 51. Final page of the Wavelength Calibration wizard
4
Xcalibur Diagnostics for the PDA Detector
Retrieving, Viewing, Printing, and Clearing the Event Log
14. Click Finish to complete the calibration.
The detector saves the calibration information. The date and time of the calibration
appear in the Wavelength Calibration area of the Calibration page (see Figure 40 on
page 49).
Retrieving, Viewing, Printing, and Clearing the Event Log
Detector errors and major detector events, such as power-on self-tests (POSTs), are logged to
a dedicated area in the memory of the detector. These messages are created as part of the
normal operation of the detector and can be helpful when you are attempting to troubleshoot
communications problems.
The log can hold up to 100 events. When the log is full, the newest entry replaces the oldest
entry. To keep a continuous record for your maintenance files, print out the log and clear it
periodically. The memory is protected by battery backup when the detector is turned off.
View, print, and clear the log weekly as part of your regular maintenance routine.
For a list of error messages that can appear in the event log along with suggested solutions, see
“Log Entries” on page 100.
Y To open, print, save, or clear the event log in the Xcalibur data system
1. Open the Accela PDA Direct Control dialog box (see “Opening the Accela PDA Direct
Occasionally, upgraded firmware becomes available for the Accela PDA Detector. Ask your
Thermo Fisher Scientific Service Representative about the availability of new firmware.
Y To check the firmware version
1. Open the Accela PDA Direct Control dialog box (see “Opening the Accela PDA Direct
Control Dialog Box” on page 34).
2. Click the Information tab.
The Information page appears (see Figure 52 on page 58).
The Versions area displays firmware version numbers for several items (see Figure 53).
Figure 53. Versions area of the Information page (Xcalibur data system)
This chapter describes the diagnostics available from the ChromQuest data system. Use the
diagnostics program to check the lamp performance, calibrate the PDA detector, and view the
PDA detector’s error log.
To perform diagnostics from the ChromQuest data system, connect the PDA detector to the
data system computer, configure the PDA detector as part of an instrument in the
ChromQuest Enterprise, and turn on the PDA detector.
If you move the PDA detector, replace lamps, install a new LightPipe flowcell, or change the
configured diode array scan rate for the detector, the system performance can change. With
use, the deuterium lamp produces less and less light so the system performance changes as the
lamp’s remaining lifetime hours decrease.
For information on configuring your Accela PDA Detector, see “ChromQuest Data System
Instrument Configuration” on page 30.
To verify the proper operation of the PDA detector, follow these procedures:
1. “Monitoring Lamp Performance from the ChromQuest Data System” on page 65
2. “Adjusting the Light Throughput with the ChromQuest Data System” on page 69
3. “Calibrating the PDA Detector from the ChromQuest Data System” on page 73
Contents
• Accessing the Direct Controls for the Accela PDA Detector
• Controlling the Lamps from the ChromQuest Data System
• Monitoring Lamp Performance from the ChromQuest Data System
• Adjusting the Light Throughput with the ChromQuest Data System
• Calibrating the PDA Detector from the ChromQuest Data System
• Displaying, Printing, and Clearing the Error Log
Accessing the Direct Controls for the Accela PDA Detector
Accessing the Direct Controls for the Accela PDA Detector
You access the direct controls and the Diagnostics dialog box for the Accela PDA detector
from the Accela PDA page (see Figure 54) of the Instrument Status window.
Y To open the Accela PDA page of the Instrument Status window
1. From the computer desktop, choose Start > All Programs > Chromatography >
ChromQuest.
The Main Menu window appears.
2. Double-click the instrument icon that represents your LC stack.
The Instrument window appears.
3. In the menu bar, choose Control > Instrument Status.
The Instrument Status window appears.
4. In the Instrument Status window, click the Accela PDA tab.
The Accela PDA page appears (see Figure 54).
Figure 54. Accela PDA page of the ChromQuest Instrument Status window
Y To open the Diagnostics dialog box for the Accela PDA Detector
1. Open the Accela PDA page of the Instrument Status window (see previous procedure).
2. Click Diagnostics.
The Accela PDA Diagnostics dialog box appears with the Lamps page displayed (see
Controlling the Lamps from the ChromQuest Data System
Controlling the Lamps from the ChromQuest Data System
From the ChromQuest data system, you can turn the lamps on or off and view the lamp’s
usage hours from the Accela PDA page of the Instrument Status window or from the Lamps
page of the Accela PDA Diagnostics dialog box.
The PDA detector keeps track of the number of hours each lamp has been operating. The
deuterium lamp has a lifetime of approximately 2000 hours and the tungsten lamp has a
lifetime of approximately 2500 hours. The useful lamp lifetime of the deuterium lamp
depends on the acceptable level of detector noise for your application (see “Lamp Lifetime
and Detector Noise” on page 5).
As lamps age, they emit less light, which results in increased baseline noise. If the noise level of
your detector signal is unacceptable and cleaning the LightPipe flowcell does not help, use the
diagnostic features of the software to determine the cause of the problem. If light output
becomes too low and adjusting the attenuators as described in “Adjusting the Light
Throughput with the ChromQuest Data System” on page 69 does not help, replace the lamps
(see “Replacing the Lamps” on page 89).
Y To control the lamps from the Lamps page
1. Open the Accela PDA Diagnostics dialog box (see “Accessing the Direct Controls for the
Accela PDA Detector” on page 62).
2. Click the Lamps tab.
The Lamps page appears (see Figure 55).
Note The intensity of the deuterium lamp falls off very slightly over a period of time
after it is turned on. Plan to wait at least one hour for the lamp to stabilize after a cold
start before collecting data in the UV region.
Figure 55. Lamps page of the Accela PDA Diagnostics dialog box
Controlling the Lamps from the ChromQuest Data System
3. Record the status and usage of each lamp.
Note Avoid indiscriminately clicking either Reset button. Click them only after you
replace their associated lamp with a new one.
Use the Lamps page in the ChromQuest data system for lamp maintenance and control.
Three direct control buttons for each lamp are available on this page: On, Off, and Reset.
Y To use the lamp controls on the Lamps page
• In the D2 Lamp area, click On to ignite the deuterium lamp.
The Status readback displays Starting during the 10-second ignition period, and then it
changes to On. If there is a problem with the lamp, the Status readback displays Failed.
• In the W Lamp area, click On to turn on the tungsten lamp.
The tungsten lamp turns on immediately. If there is a problem with the lamp, the Status
readback displays Failed.
• Click Reset to reset the stored total run time for the associated lamp to zero and update
the Last Reset readback to the current date and time. After you replace a lamp, reset its
lamp usage hours to zero.
Monitoring Lamp Performance from the ChromQuest Data System
Monitoring Lamp Performance from the ChromQuest Data System
With use, the deuterium lamp emits less and less light. As the light output from the
deuterium lamp decreases, the detector noise increases. For information on the typical lamp
lifetime, see “Controlling the Lamps from the ChromQuest Data System” on page 63.
To monitor and track lamp performance from the ChromQuest data system, follow these
procedures:
• Viewing an Intensity Scan from the ChromQuest Data System
• Recording the Performance of the Lamps
Viewing an Intensity Scan from the ChromQuest Data System
Y To monitor lamp performance from the ChromQuest data system
1. Open the Instrument window for your LC system:
a.From the computer desktop, choose Start > All Programs > Chromatography >
ChromQuest.
The Main Menu window appears.
b.Double-click the icon that represents your LC stack.
The Instrument window appears.
2. Create and download a method that pumps 100% HPLC-grade methanol or
HPLC-grade water at a constant flow rate of 1 mL/min.
3. Turn on the lamps and check their status (see “Controlling the Lamps from the
ChromQuest Data System” on page 63).
Wait for one hour for both lamps to equilibrate.
4. Open the Accela PDA Diagnostics dialog box (see “Accessing the Direct Controls for the
Accela PDA Detector” on page 62).
5. Click the Control tab.
The Control page appears.
6. In the Mode area, select the Intensity option.
7. Click Default, and then verify that the following parameters are specified in the
Spectrum area (see Figure 56):
Monitoring Lamp Performance from the ChromQuest Data System
Figure 57. Display page (after you click On in the Status area, but before you click Start)
12. On the right side of the page, in the Status area, click On.
13. In the Data area, click Start to refresh the display.
14. Save a printout or an electronic copy of the spectrum. Date the printout and add it to
your maintenance records (see “Recording the Performance of the Lamps” on page 68).
Monitoring Lamp Performance from the ChromQuest Data System
Recording the Performance of the Lamps
Use following procedures to record the spectrum data on the Display page:
• Using the Print Screen Button
• Using the Print Utility
• Tak in g a S na p sh ot
Using the Print Screen Button
Y To store the spectral data using the print screen button
1. As you collect the data stream on the Display page, press SHIFT+PRINT SCREEN.
2. Open Microsoft™ Paint and save the screen capture as a bitmap or open Microsoft Word
and paste the screen capture into a Word document.
Using the Print Utility
Taking a Snapshot
Use the ChromQuest print utility to print a copy of the Spectrum window.
Y To use the print utility
1. On the Display page, place the cursor in the Spectrum window and right-click.
2. From the shortcut menu, choose Utilities > Print.
Use the snapshot option to create a Microsoft Excel™ comma-separated values (CSV) file that
contains information about the spectrum on the Display page. The data system stores this file
with the name WaveData.csv in the ChromQuest directory. The file three columns: diode
number, wavelength, and intensity value.
Note The data system appends the file with a date and time stamp. The data stamp
consists of six digits; the first two digits are the month, followed by two digits for the day
and two digits for the year. The time stamp consists of six digits; the first two digits are the
hour in military time, followed by digits for the minutes and two digits for the seconds.
Y To take a snapshot and view the stored information
1. On the Display page, stop the data stream by clicking Stop in the Data area.
2. Click Snapshot.
3. Using Microsoft Windows™ Explorer, browse to the ChromQuest directory.
Adjusting the Light Throughput with the ChromQuest Data System
Adjusting the Light Throughput with the ChromQuest Data System
The Accela PDA Detector has two attenuators that control the light throughput from the
lamps.
Decreasing light throughput increases baseline noise. Increasing light throughput can saturate
the diode array. When the array is saturated, the response from the Accela PDA Detector is a
flat baseline.
Adjust the attenuators as the light output from the deuterium lamp decreases and whenever
you do the following:
• Replace either lamp (see “Replacing the Lamps” on page 89)
• Replace the LightPipe flowcell (see “Installing the LightPipe Flowcell” on page 17)
• Change the configured diode array scan rate (see Chapter 3, “Configuration.” )
Tip As the diode array scan rate increases, the sampling time per diode decreases. The
integrated light intensity viewed on the Display page is a function of the light throughput
to the diode array and the sampling time per diode. So when you change the diode array
scan rate, you must adjust the light throughput.
• If you increase the diode array scan rate (for example, from 20 Hz to 80 Hz), you
must increase the light throughput to achieve the same intensity counts.
• If you reduce the diode array scan rate (for example, from 80 Hz to 20 Hz), you must
reduce the light throughput to avoid saturating the array.
Pushing the attenuator tabs upward increases the light throughput to the diode array.
Pushing the attenuator tabs down decreases the light throughput to the diode array. (See
Figure 20 on page 25.)
Check the light intensity by following the Operational Verification procedure and adjust the
attenuators to provide light intensities in the specified operating ranges.
Note Before you adjust the attenuators, replace the column with a flow restrictor, and set
the pump to deliver HPLC-grade water at a flow rate of 1 mL/min through the flowcell.
To adjust the light throughput from the lamps, follow these procedures:
1. Setting Up the Spectral and Discrete Channel Displays
Adjusting the Light Throughput with the ChromQuest Data System
Setting Up the Spectral and Discrete Channel Displays
Y To set up the spectral and discrete channel displays
1. Open the Diagnostics dialog box for the Accela PDA Detector (see “Accessing the Direct
Controls for the Accela PDA Detector” on page 62).
2. Turn on both lamps (see “Controlling the Lamps from the ChromQuest Data System” on
page 63).
3. Download the parameters for the spectral display:
a.Click the Control tab.
The Control page appears (see Figure 56 on page 66).
b.In the Mode area, select the Intensity option.
c.Click Default, and then verify that the following parameters are specified:
Start = 2
End = 511
Step = 1
d.Click Load To Detector.
4. Determine the diodes of maximum output for the lamps as follows:
• From the spectrum displayed, determine and record the pixel of maximum intensity
within the 10 to 40 diode range. This is the diode of maximum output for the
deuterium lamp.
• From the spectrum displayed, determine and record the pixel of maximum intensity
within the 400 to 500 diode range. This is the diode of maximum output for the
tungsten lamp. Ignore the spike at approximately diode number 380. This spike is an
emission line of the deuterium lamp.
5. Turn off the data stream as follows:
a.In the Status area, click Off .
b.In the Data area, click Stop.
6. Set the discrete channel displays as follows:
a.Click the Control tab to return to the Control page.
b.In the Channel A box, type the value for the diode of maximum intensity for the
deuterium lamp.
c.In the Channel C box, type the value for the diode of maximum intensity for the
Use the attenuator tabs (see Figure 20 on page 25) on the front panel of the PDA detector to
adjust the light throughput to the diode array.
Y To adjust the attenuators
1. Set up the spectral and discrete channel displays (see “Setting Up the Spectral and
Discrete Channel Displays” on page 70).
2. Click the Display tab.
The Display page appears.
3. As you view the discrete channel display (see Figure 58), do the following:
• Adjust the left attenuator tab (UV attenuation) to achieve a Channel A value as close
as possible to 900000 without saturating the array.
• Adjust the right attenuator tab (Visible attenuation) to achieve a Channel C value as
close as possible to 900000 intensity counts as possible without saturating the array.
5
ChromQuest Diagnostics for the PDA Detector
Adjusting the Light Throughput with the ChromQuest Data System
Figure 59 and Figure 60 on the next page show saturation of the diode array.
Figure 58. Display page (after you click On in the Status area and Start in the Data area)
Calibrating the PDA Detector from the ChromQuest Data System
Calibrating the PDA Detector from the ChromQuest Data System
To calibrate the PDA detector from the ChromQuest data system, follow these procedures:
1. Preparing the PDA Detector for Calibration
2. Performing an Array Calibration from the ChromQuest Data System
3. Performing a Wavelength Calibration from the ChromQuest Data System
Preparing the PDA Detector for Calibration
Y To prepare the Accela PDA Detector for calibration
1. Replace the LC column with a flow restrictor.
2. Set up the system to pump HPLC-grade water or HPLC-grade methanol through the
flowcell, and then start the solvent flow.
3. Turn on both lamps and wait one hour for the D2 lamp to equilibrate (see “Controlling
the Lamps from the ChromQuest Data System” on page 63).
4. Verify that the diode array is not saturated (see “Adjusting the Light Throughput with the
ChromQuest Data System” on page 69).
Performing an Array Calibration from the ChromQuest Data System
The Array calibration measures and corrects for the dark current produced by the diodes of
the photodiode array. The dark current is the small amount of background signal that is
produced by the diodes of the array even when both lamps are turned off. Typical dark current
values range from 2000 to 4000 counts.
The environmental conditions of your laboratory can cause the dark current of the diode
array to increase over time. For best results, perform an array calibration (dark current) after
any of the following events occurs:
• After 100 hours of use or monthly, whichever comes first
• Whenever a significant temperature change occurs
•After you move the detector
• After you replace the lamps
Because the dark current produced by the diodes rises as the temperature within the detector
rises, make sure that you warm up the lamps for one hour before you perform a dark current
calibration. Warming up the lamps for one hour equilibrates the detector to its normal
operating temperature.
Calibrating the PDA Detector from the ChromQuest Data System
The PDA detector briefly turns the lamps off as it performs the dark current calibration
routine. After it completes the dark current calibration, the PDA detector turns the lamps
back on.
Note The dark current calibration program does not run when data collection is enabled
on the Display page.
Y To perform a dark current calibration of the diode array
1. Prepare the PDA detector for calibration (see “Preparing the PDA Detector for
Calibration” on page 73).
2. Open the Diagnostics dialog box for the Accela PDA Detector (see “Accessing the Direct
Controls for the Accela PDA Detector” on page 62).
3. Click the Calibration tab.
The Calibration page appears.
4. In the Array area, click Execute.
A message box appears (see Figure 61).
Figure 61. Calibration preconditions dialog box
5. Make sure that the lamps are warmed up, that the pump is running at 1 mL/min, and
that the filter wheel is in position 1 (see Figure 20 on page 25), and then click OK.
The status of the calibration procedure appears by the Status readback area on the
Calibration page. During the dark current calibration, the lamps turn off before the data
system collects the intensity scans. After the last calibration event, the lamps turn back on.
6. Click OK to finish the calibration.
The date and time of the calibration appear in the Array area of the Calibration page and
are stored in the PDA detector’s memory.
Calibrating the PDA Detector from the ChromQuest Data System
Performing a Wavelength Calibration from the ChromQuest Data System
The alignment of the spectrum on the diode array depends upon the physical alignment of
various components of the optical bench. The alignment can become offset if the detector is
sharply jolted, in shipping, for example. Such bumps and jars can slightly change the
wavelength of light reaching the photodiode array. The automated wavelength calibration
determines the wavelength accuracy of the detector and uses the detector’s wavelength
algorithm to correct any misalignment.
Y To perform a wavelength calibration with ChromQuest
1. Open the Accela PDA Diagnostics dialog box (see “Accessing the Direct Controls for the
Accela PDA Detector” on page 62).
2. Click the Calibration tab.
The Calibration page appears (see Figure 62).
Figure 62. Calibration page of the Accela Diagnostics dialog box
b.Select an appropriate wavelength calibration file from the list.
An appropriate wavelength file should include the range of wavelengths that you use
under normal operating conditions.
c.Click Open.
Note ChromQuest has four calibration files to choose from. The HolmiumUV
file contains five wavelengths in the UV region while the other files, such as
Holmium12, use sets of wavelengths from both the UV and Visible wavelength
regions. The holmium oxide absorbance maxima are selected from a spectrum
published in “Holmium Oxide Solution Wavelength Standard from 240 to
640 nm - SRM 2034 (NIST Special Publication 260-54).”
The holmium oxide bands of the selected file appear in the Wavelength File area
(see Figure 64).
Calibrating the PDA Detector from the ChromQuest Data System
Figure 64. Wavelength File area with the Holmium12 Wavelength Calibration File
selected
4. In the Wavelength area, click Execute.
A message box appears (see Figure 65).
Figure 65. Calibration preconditions
5. If all of the preconditions are met, click OK.
The data system collects a background spectrum, which it uses to remove the absorbance
contribution of the mobile phase. When the background collection is complete, another
message box appears (see Figure 66).
Calibrating the PDA Detector from the ChromQuest Data System
Figure 66. Message prompting you to move the filter wheel to position 2
6. Move the filter wheel to position 2 as directed, and then click OK.
The detector takes a holmium oxide scan, performs iterative calculations while applying
the rise time and bandwidth filters, and then displays a new message box (see Figure 67).
Figure 67. Calibration message prompting you to return the filter wheel to position 1
7. Move the filter wheel back to position 1, and then click OK to close the message box and
view the results.
8. In the Wavelength File area, check the delta values (see Figure 68).
a.If the delta values are not within the range of ±1 nm, repeat the wavelength
calibration procedure for verification.
b.If, after applying a new calibration, the delta values are still not within the range of
±1 nm, call your Thermo Fisher Scientific service representative for assistance.
Detector errors and major detector events, such as power-on self-tests (POSTs), are logged to
a dedicated area in the memory of the detector. These messages are created as part of the
normal operation of the detector and can be helpful when attempting to troubleshoot
communications problems.
The log can hold a maximum of 100 errors/events. When the log is full, the newest entry
replaces the oldest entry. To keep a continuous record for your maintenance files, print out the
log and clear it periodically. The memory is protected by battery backup when the detector is
turned off. View, print, and clear the log weekly as part of your regular maintenance routine.
For a list of some common error messages that might appear in the log, see “Log Entries” on
page 100.
Y To display, print, and clear the error log in the ChromQuest data system
1. Open the Error Log page:
a.Open the Diagnostics dialog box (see “Accessing the Direct Controls for the Accela
PDA Detector” on page 62).
b.Click the Error Log tab.
The Error Log page appears (see Figure 69).
Figure 69. Error Log page
2. Use the buttons in the Error log page to do the following:
• Click Get to retrieve and display the error log information from the detector.
Figure 69 shows a sample Error Log.
• Click Print to print a copy of the displayed log.