Jenway 7305 User Manual

Spectrophotometers

Models 7300 & 7305

Operating Manual

730 005 REV E /12-10

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Safety

Please read this information carefully prior to installing or using this equipment.

1.The unit described in this manual is designed be operated only by trained personnel. Any adjustments, maintenance and repair must be carried out as defined in this manual, by a person qualified to be aware of the hazards involved.

2.It is essential that both operating and service personnel employ a safe system of work, in addition to the detailed instructions specified in this manual.

3.Other than for those items defined in the maintenance procedures herein there are no user serviceable items in this instrument. Removal of covers and attempted adjustment or service by unqualified personnel will invalidate the warranty and may incur additional charges for repair.

4.References should always be made to the Health and Safety data supplied with any chemicals used. Generally accepted laboratory procedures for safe handling of chemicals should be employed.

5.If it is suspected that safety protection has been impaired in any way, the unit must be made inoperative and secured against any intended operation. The fault condition should immediately be reported to the appropriate servicing authority.

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Contents

		Page
Safety		3
Section 1 - Introduction		8
1.1	Instrument description	8
1.2	Instrument specification	8
Section 2 - Installation		9
2.1	Unpacking	9
2.2	Installation	9
2.3	Display	10
2.4	Controls	11
2.5	Rear panel	12
2.6	Front panel	12
Section 3 - Theory and practice of spectroscopy measurements		13
3.1	Theory of spectroscopy measurement	13
3.2	Spectroscopy measurement	13
3.3	Good practice guidelines	14
Section 4 - Instrument setup		16
4.1	Navigating and screen setup	16
4.2	Time and date	17
4.3	Instrument settings menu	17
4.4	Diagnostics	18
4.5	Screen contrast	18
4.6	Lamp save	18
Section 5 - Photometrics		20
5.1	Mode specific parameters	20
5.2	Method set up	20
5.2.1	Selecting a wavelength	21
5.3	Calibration	21
5.4	Sample measurment	21
Section 6 - Concentration		22
6.1	Mode specific parameters	22
6.2	Method setup	22
6.2.1	Selecting a wavelength	22
6.2.2	Settings	23
6.2.2.1	Selecting concentration units	23
6.2.2.2	Changing the resolution	24
6.2.2.3	Using a standard	24
6.2.2.4	Using a factor	24
6.3	Calibration	24
6.3.1	Calibrating to a standard	24

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6.3.2	Calibrating to a factor	25
6.4	Sample measurement	25
6.4.1	Measuring a sample after calibrating to a standard	25
6.4.2	Measuring a sample after calibrating to a factor	25
SECTION 7 – PRINTING AND AUTOLOGGING		26
7.1	Printing	26
7.1.1	Print Setup	26
7.1.2	Printing Results	27
7.2	Autologging	27
7.2.1	Setting the Number of Sample Repetitions	27
7.2.2	Selecting Result’s Destination	28
7.3	Connecting to a PC	28
Section 8 - Accessories and spare parts		29
8.1	Optional accessories	29
8.2	Connecting the accessories	29
8.2.1	Internal printer	29
8.2.2	Passive accessories	30
8.2.3	Active accessories	30
8.2.3.1	Automatic 8 cell turret	31
8.2.3.2	Peltier	31
8.2.3.3	Sipper pump	32
8.2.3.4	Combined sipper peltier pump	33
8.3	Using the accessories	34
8.3.1	Automatic 8 cell turret	34
8.3.2	Peltier	34
8.3.3	Sipper pump	35
8.3.3.1	Manual sipper pump settings	35
8.3.3.2	Timed sipper pump settings	36
8.3.4	Combined sipper peltier pump	38
8.4	Spares	39
Section 9 - Maintenance and service		40
9.1	Routine maintenance	40
9.2	Lamp replacement	40
9.2.1	Tungsten halogen lamp replacement	40
9.2.2	Xenon lamp module replacement	40
9.3	Service	41
Section 10 - Troubleshooting		42
10.1	Error codes	42
10.2	Troubleshooting guide	44
10.3	Technical support	44
Section 11 - Declaration of conformity		45
Section 12 - Glossary of icons		47
Index		54

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Section 1 - Introduction

1.1INSTRUMENT DESCRIPTION

The 7300 and 7305 spectrophotometers are suited to a wide range of applications in education, quality control, environmental and clinical analysis. The 7300 is a visible spectrophotometer covering a wavelength range from 320nm to 1000nm. The 7305 is a UV/Visible spectrophotometer with a wavelength range from 198nm to 1000nm. Both models feature measurement modes for absorbance, % transmittance and concentration. These instruments use icon driven software and have an improved navigation system for easy and intuitive usability.

1.2inSTRUMENT SPECIFICATION

	7300	7305
Wavelength
Range	320 to 1000nm	198 to 1000nm
Resolution		1nm
Accuracy		± 2nm
Repeatability		± 0.5nm
Spectral bandwidth		5nm
Photometrics

Transmittance Absorbance Accuracy Resolution Stray light

Concentration

Range

Resolution

Calibration

Units

Factor

Standard

Other

Beam height Light source Lamp save GLP Outputs Power

Size (w x d x h) Weight

0 to 199.9% -0.300 to 2.500A

±1%T, ±0.01Abs at 1.000 Absorbance

	0.1%T, 0.001A
<0.5% at 340nm	<0.5% at 340nm and 220nm

-300 to 9999 Selectable 1/0.1/0.01/0.001

Blank with a single standard or factor

no units, %, ppm, EBC, SRM, mEq/l, mEq, M, mM, µM, nM, U, U/l, U/ml, g/l, mg/l, µg/l, ng/l, g/dl, mg/dl, µg/dl, mg/ml, µg/ml, ng/ml, µg/µl, ng/µl, mol/l, mmol/l

0.001 to 10000

0.001 to 1000

	15mm
Tungsten halogen lamp	Xenon lamp
Yes	Not applicable

Current time and date

USB, Analogue, RS232, Internal printer 24V

275 x 400 x 220mm 6kg

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Section 2 - Installation

2.1UNpACking

Remove the 7300 or 7305 from the packaging and ensure the following items are included:

1.Model 7300 spectrophotometer (730 001), or Model 7305 spectrophotometer (730 501)

2.24V 65W power supply unit (021 060)

3.Pack of 100 disposable plastic visible wavelength cuvettes (060 084), or pack of 100 disposable UV plastic cuvettes (060 230)

4.Jenway 73 series PC software (735 100) and interface cable (013 203)

5.Instruction manual (730 005)

6.Jenway Foreign Manual CD (JENMANCD)

7.Optional accessories (as ordered)

2.2inSTALLATION

Models 7300 and 7305 are supplied ready to use.

The unit should be placed on a clean flat surface which is free from drafts and vibrations. The units are designed for operation on 90V to 264V AC input at 47 to 63Hz. Select the correct plug attachment and attach to the power supply unit as shown below:

Fig 2.2.1 – Power supply unit with various plugs

Connect the power supply unit to the power inlet socket on the rear panel of the instrument and connect to the mains socket. Turn the power on at the mains and switch the instrument on using the power switch on the rear of the instrument.

The instrument will perform several power on tests before displaying the main menu:

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1

2

7300

3

4

09:02

Fig 2.2.2 – All Power On Tests Complete

1.Instrument check – ensures the validity of the saved parameters

2.Dark test

3.Checks for the accessory fitted. If an active accessory is found the instrument verifies communication and response

4.Self calibration of wavelengths

2.3DISPLAY

These spectrophotometers have a dot matrix display which enables icons and graphs to be displayed clearly. Following successful completion of the power on tests the main menu screen will be displayed:

7300

1	5

09:02

2

3

4

Fig. 2.3.1 – Display

1.Photometrics measurement mode

2.Back key

3.Time and date menu

4.Instrument settings menu

5.Concentration measurement mode

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2.4CONTROLS

The keypad used for these models enables an easy and effective way of navigating the different measurement modes, entering numbers, saving and analysing results. The soft keys are active when an icon is displayed above or adjacent to the key. The only exception to this is the back key which is always active.

The main menu screen and surrounding keypad is displayed below.

	7300
1	5
1	5
	09:02
2

3

4

Fig. 2.4.1 – Display

1.Photometrics measurement mode

2.Back key

3.Time and date menu

4.Instrument settings menu

5.Concentration measurement mode

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2.5REAR PANEL

The image below shows the rear panel on the instrument:

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3

4

5

1

		Fig. 2.5.1 – Rear Panel
1.	Lamp access panel	Allows access to lamp when replacement is necessary
2.	Power switch	On/off switch for the unit
3.	Power in socket	Connection socket for power supply unit
4.	RS232 serial port	Connection to a PC or external serial printer
5.	Output sockets	Analogue output

2.6FRONT PANEL

The image below shows the front panel of the instrument:

1

2 4

3

Fig. 2.6.1 – Front Panel

1.Integral printer (optional accessory)

2.Keypad

3.Instrument lid

4.Display

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SECTION 3 – Theory and Practice of Spectroscopy Measurements

3.1THEORY OF SPECTROSCOPY MEASUREMENT

UV-visible spectroscopy is the measurement of the absorbance of light at a specific wavelength in a sample. This is used to identify the presence and concentration of molecular entities within the sample. The Beer-Lambert law is used to relate the absorption of light to the properties of the sample through which the light is travelling through. The Beer-Lambert law states that:

A is the absorbance

is the molar absorption coefficient (l mol-1cm-1) c is the concentration (mol l-1)

l is the path length (cm)

This law shows that absorbance is linear to concentration but this is only true for low concentrations. For absorbance levels above 3 the concentration starts to move away from the linear relationship.

Transmittance is the proportion of the light which passes through the sample:

						Where:
Io					It	Lo	is the incident light
						lt	is the transmitted light
						l	is the path length

l

Therefore: T = It

Io

Absorbance is inversely related to transmittance:

A = log 1

T

3.2SPECTROSCOPY MEASUREMENT

There are four main components of a spectrophotometer. These are a light source to emit a high and constant amount of energy over the full wavelength range; a method for separating the light into discreet wavelengths; a sample holder and a light detector.

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The optical layout of the 7300 and 7305 spectrophotometers is shown below:

Lamp

Entrance slit

Grating

Collimator mirror

Exit Slit

Detector

Sample	Collecting Lens

Figure 3.2.1 – Diagram of light path

The light from the pre-focused tungsten halogen (7300) or pre-aligned xenon (7305) lamp is focused onto the grating, with 1200 lines per millimeter, which separates the light into discreet wavelengths. The diffracted spectrum of light then passes through a further slit and lens arrangement before passing through the sample in the sample chamber from left to right. The light which is not absorbed by the sample is transmitted through a collecting lens and onto the signal detector. The photo-diode detector used is mounted directly onto the detector PCB and is used to calculate the % transmittance. The result is displayed either as % transmittance or absorbance on the instrument display.

3.3GOOD PRACTICE GUIDELINES

1.For optimum performance all spectrophotometers should be sited in a clean, dry, dust free atmosphere. When in use ambient temperature and light levels should remain as constant as possible.

2.If required adherence to Standard Operating Procedures (SOP) and Good Laboratory Practice (GLP) should be monitored with regular calibration checks and a suitable Quality Control (QC) programme.

3.The sample chamber lid must be fully closed during measurement and before any readings are recorded or printed.

4.The correct selection of sample containers is imperative for accurate and reproducible results:

a)Check that the material of the sample container is compatible with the wavelengths to be used for measurement. In general glass can only be used down to 360nm or 320nm depending on quality. Standard plastic cuvettes can be used down to 320nm. Special UV versions can be used down to 260nm. Below this level quartz cuvettes must be used.

b)Plastic disposable cuvettes should only be used ONCE.

c)Glass cuvettes should be thoroughly cleaned after use. Discard when scratches become evident on optical surfaces.

d)Care should be taken when selecting semi-micro or micro cuvettes. The cuvette window on the

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inner chamber (the area filled with sample) must be wider than the aperture in the sample holder or light will reach the detector without passing through the sample. In this case, semi-micro or micro cuvettes with self-screening black surrounds must be used or, alternative holders for these cuvettes should be used.

e)Glass test tubes and other sample tubes should be used with care. Where possible, matched tubes should be used and any index mark set to the correct position before measurements are made.

f)Ensure any sample containers used are compatible with the constituents of both the samples and standards they are to hold. Plastic cuvettes are not compatible with organic solvents.

g)All sample containers must be handled with care; by the top, bottom and non-optical surfaces only. Any finger marks evident must be removed by a suitable cleaning process.

h)Flow-through cuvettes must be selected with care and consideration for the sample type, sample volume, pumping system, rinse, sample and waste handling to be used.

5.Samples and standards should not be stored in open cuvettes or sample containers as evaporation will change the value and lead to staining of the walls which may be irreversible. If stored in stoppered and sealed cuvettes, they should be filled with little or no air space and the values regularly checked against a reference standard or quality control material.

6.Samples should be allowed to equilibrate to ambient temperature before measurement (unless a suitable temperature controlled sample holder is in use). Temperature change during measurement may cause air bubbles to form on the walls of the sample holder. This is a common cause of drift during measurement.

7.In the preparation of samples and standards high grade borosilicate glass and AR grade chemicals and reagents must be used. Good quality deionised water or other suitable solvents must be used for dissolving or diluting samples, chemicals and reagents.

8.All measurements require calibration to a blank, for maximum accuracy this should be prepared with care using the same deionised water or solvent used for dissolving or diluting the sample. Where reagents are added to the sample to produce a colour proportional to its concentration a ‘sample based’ blank should be used. In this case the blank should consist of all reagents or chemicals to be used, except the sample which will produce the colour to be measured.

9.Deviations from the Beer-Lambert Law may occur at high and low concentrations giving non-linear response during sample concentration measurements. For all new methods a linear range should be defined by the preparation of a calibration curve.

10.Cuvettes and sample holders must be filled to a minimum level which covers the light path. All Jenway spectrophotometers have a beam height of 15mm.

11.The instrument must be calibrated to zero absorbance/100% transmittance prior to taking readings.

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SECTION 4 – Instrument Setup

4.1NAVIGATING AND SCREEN SETUP

The main menu screen is displayed below.

	7300	Concentration
		measurement
		mode
Photometrics	09:02
measurement		Instrument
mode
		settings menu

Back key		Time and date menu

Fig 4.1.1 – Home Screen

To navigate around the spectrophotometer screen press the soft keys adjacent to icons displayed on the screen. In the main menu either of the two soft keys adjacent to the measurement mode icon can be pressed to access the mode. There is a back key which returns to the previous menu without saving any changes.

The main menu screen provides access to the measurement modes, the time and date menu and the instrument settings menu. The measurement modes are photometrics and concentration. The instrument settings menu enables access to the screen contrast and lamp save menus.

0.000ABS

100.0%T

400nm

All of the measurement modes open initially into a minimal operating menu. This menu allows calibration and simple readings to be taken without changing any measurement parameters. Pressing the key adjacent to the JW icon opens the expanded operating menu.

09:02

Minimal Operating Menu

0.000ABS

100.0%T

400nm

09:02

Expanded Operating Menu (Photometrics measurement mode)

This menu enables changes to measurement parameters and settings to be made. Depending on the mode, the measurement parameters can be accessed through the settings menu which is displayed in the top right hand corner of the screen. The only mode where this function is not available is the photometrics mode; instead a toggle icon is displayed which is used to change the primary and secondary displays.

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