SPECTROPHOTOMETER OPERATONAL MANUAL V 1.0 Revision 1

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SPECTROPHOTOMETER

OPERATONAL MANUAL

V 1.0

Revision 1

For Alpha-1101, 1102, 1502

Laxco, Inc.

www.laxcoinc.com

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TABLE OF CONTENTS

General information ........................................................................................................................ 3 Safety ...................................................................................................................................... 3 Electrical ................................................................................................................................. 3 Warning................................................................................................................................... 3 Performance ............................................................................................................................ 3 Radio Interference ................................................................................................................... 4 Introduction ............................................................................................................................. 4 Working Principle ................................................................................................................... 4 Unpacking Instructions ........................................................................................................... 5 Specifications .......................................................................................................................... 5 Installation: ............................................................................................................................. 5 Operational Panel .................................................................................................................... 7

Description of Keys ................................................................................................................ 7 Operation Instruction: ..................................................................................................................... 8

Prepare the spectrophotometer ................................................................................................ 8

BASIC MODE ━ %T/Abs Measure ...................................................................................... 9

Quantitative Test ................................................................................................................... 11 Run test ......................................................................................................................... 11 All Test List .................................................................................................................. 12 Define a un-defined test in All Test List ....................................................................... 13

By Known Factors ................................................................................................ 13 By Standard ........................................................................................................... 16

UTILITY ............................................................................................................................... 18 Wavelength Calibration ................................................................................................ 18 Collecting Dark Current ................................................................................................ 19

Edit Clock ..................................................................................................................... 19 System Baseline ............................................................................................................ 20 Turn on/off Deuterium Lamp........................................................................................ 20 Turn on/off Tungsten Halogen Lamp ........................................................................... 20 Reset Defaults ............................................................................................................... 20

Memory Manager.......................................................................................................... 20 Wavelength Correction ................................................................................................. 21

PC LINK ............................................................................................................................... 22 Wavelength Calibration: ............................................................................................................... 22

Holmium Oxide Filter Method: ............................................................................................ 23

Didymium Filter Method: ..................................................................................................... 23 Absorbance Accuracy Checks ...................................................................................................... 24

Stray Light Check ......................................................................................................................... 25 Trouble Shooting: ......................................................................................................................... 25 Error Codes Definitions: ............................................................................................................... 27

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General information The apparatus described in this manual is designed to be used by properly trained personnel

in a suitable equipped laboratory. For the correct and safe use of this apparatus it is essential that

laboratory personnel follow generally accepted safe procedures in addition to the safety

precautions called for in this manual.

The covers on this instrument may be removed for servicing. However, the inside of the

power supply unit is a hazardous area and its cover should not be removed under any

circumstances. There are no serviceable components inside this power supply unit. For all

instruments, avoid touching the high voltage power supply at all times.

Some of the chemicals used in spectrophotometry are corrosive and/or inflammable and

samples may be radioactive, toxic, or potentially pathogens. Care should be taken to follow the

normal laboratory procedures for handling chemicals and samples.

Safety Read the following before installing and using the instrument and its accessories. The

instruments mentioned in this manual should be operated by appropriate laboratory technicians.

Electrical The power cord shall be inserted in a socket provided with a protective earth contact. The

protective action must not be negated by the use of an extension cord without a protective

conductor.

Warning Any interruption of the protective conductor inside or outside the apparatus or disconnection

of the protective earth terminal is likely to make the apparatus dangerous. Intentional

interruption is prohibited.

Whenever it is likely that the protection has been impaired, the apparatus shall be made

inoperative and be secured against any unintended operation. NEVER touch or handle the power

supply on the Alpha-1502 due to the high voltage.

The protection is likely to be impaired if, for example, the apparatus

Shows visible damage

Fails to perform the intended measurements

Has been subjected to prolonged storage under unfavorable conditions.

Has been subjected to severe transport stresses

Performance To ensure that the instrument is working within its specification, please verify proper

operation before making important measurements, carry out performance checks for this

particular reference to wavelength and absorbance accuracy. Performance checks are detailed in

this manual.

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Radio Interference For compliance with the EMC standards referred to in the EC Declaration of Conformity, it

is necessary that only shielded cables supplied by the factory be used when connecting the

instrument to computers and accessories.

Introduction The Alpha series are single beam, general purpose instruments designed to meet the needs of

the Conventional Laboratory. They are ideal for various applications, such as: Clinical

Chemistry, Biochemistry, Petro chemistry, Environmental Protection, Food and Beverage Labs,

Water and Waste Water Labs and other fields of quality control and research.

The Alpha Series features a LCD display of photometric result, easy operation and

wavelength range of 325nm to 1000nm (200-1000nm for Alpha-1502), these instruments are

ideal for measurements in the visible wavelength region of the electromagnetic spectrum,

(ultraviolet and visible for the Alpha-1502).

Working Principle The spectrophotometer consists of five parts: 1) Halogen and deuterium if Alpha-1502, lamp

to supply the light; 2) A Monochromator to isolate the wavelength of interest and eliminate the

unwanted second order radiation; 3) A sample compartment to accommodate the sample

solution; 4) A detector to receive the transmitted light and convert it to an electrical signal; and

5) A digital display to indicate absorbance or transmittance. The block diagram below illustrates

the relationship between these parts.

Block diagram for the Spectrophotometer

In your spectrophotometer, light from the lamp is focused on the entrance slit of the

monochromator where the collimating mirror directs the beam onto the grating. The grating

disperses the light beam to produce the spectrum, a portion of which is focused on the exit slit of

the monochromator by a collimating mirror. From here the beam is passed to a sample

compartment through one of the filters, which helps to eliminate unwanted second order

radiation from the diffraction grating. Upon leaving the sample compartment, the beam is passed

to the silicon photodiode detector and causes the detector to produce an electrical signal that is

displayed on the digital display.

The Alpha Series incorporates an USB1.0 for connecting to a PC via the Application

Software and a RS232 port for the built-in thermal printer.

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Unpacking Instructions

Carefully unpack the contents and check the materials against the following packing list to

ensure that you have received everything in good condition:

Packing List

Description: Quantity

Spectrophotometer...........……................. ….......................... .. 1

Power Cord…………………………………....…......……….. 1

Cuvettes..................................……............... …........……….. Set of 4, glass

Set of 2, quartz (Alpha-1502 only)

Operational Manual................................................………......... 1

Dust Cover……………………………………………………... 1

Specifications

Alpha-1101 Alpha-1102 Alpha-1502

Wavelength Range 325-1000nm 200-1000nm

Spectral Band pass 4nm

Wavelength Accuracy +2 nm

Wavelength

Repeatability ≤1nm

Stray Radiant Energy ≤0.1@ 360 and 400nm ≤0.1 @ 220 and 340nm

Photometric Range 0 to 125%T -0.3 to 2.5 Abs -9999 to 9999

Photometric Accuracy ±0.5%T(0～100%T)

Data output USB1.0 and Optional Built in Printer

Power Requirements 85-240Vac, 50-60 Hz

Dimensions 450W x 370D x 200H 570W x 460D x 230H (mm)

Light Source Tungsten Halogen Tungsten

Halogen/Deuterium

Weight 8kg 13.5kg 14.2kg

Installation:

1. After carefully unpacking the contents, check the materials with the packing list, this page, to

ensure that you have received everything in good condition.

2. Place the instrument in a suitable location away from direct sunlight. In order to have the best

performance from your instrument, keep it as far as possible from any strong magnetic or

electrical fields or any electrical device that may generate high-frequency fields. Set the unit up

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in an area that is free of dust, corrosive gases and strong vibrations.

3. Remove any obstructions or materials that could hinder the flow of air under and around the

instrument.

4. Turn on the instrument and allow it to warm up for at least 15 minutes before taking any

readings.

Back View of Alpha-1502

Power Cord Inlet

On/Off Switch

Light View hole

Air Vent

USB1.0 Cooling Fan

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Operational Panel

Description of Keys

【CLEAR/LOAD】 Clear number or character in edition in Quantitative

Mode, Load data or curve saved before;

【PRINT/SAVE】 Print data , Save data or curve;

【0Abs/100%T】 Set 0Abs and 100%T;

【EXIT】 Exit to previous screen;

【ENTER】 Confirm the inputted data or selected item; Go to next

setup or screen;

WL/Conc./F

【∧】,【∨】 Set Wavelength, Standard solution value and Standard

solution Factor value;

Menu Scroll

【∧】,【∨】 Browse the items in the menu

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Operation Instruction:

Prepare the spectrophotometer

Turn on the spectrophotometer by pressing the Power Switch (IO). The screen displays

sequentially as Fig 6. Pressing EXIT or after 15 minutes warm up, the instrument will locate

lamp(Alpha-1502) and filter, then main menu displays as Fig 7.

Fig 6

Note: By different mode, the second line display in Fig 6 may be “Alpha-1102” or

“Alpha-1502”

Fig 7

Note: a. If the saved wavelength has been out of order, “WL calibrating” will be

implemented and then will go into Main Menu.

b. It is strongly recommended that taking dark current measurements following the

steps below after warm-up.

b. 1 Select UTILITY in Fig 7 and then select Dark Current in Fig 8.1

Fig 8.1

b. 2 Dark Current will be taken shown as Fig 8.2 and be saved shown as Fig

8.3 after pressing EXIT

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Fig 8.2

Fig 8.3

BASIC MODE ━ %T/Abs Measure

1. In Fig 7, scroll * to BASIC MODE and then press ENTER to Select basic T/Abs mode.

Showed as Fig 9.If the readouts are not 100.0%T and 0.000A, you may press

0Abs/100%T to blank.

Fig 9 BASIC MODE

2. Select the desired wavelength by pressing the appropriate key. At any time that the

wavelength is changed, blank will automatically be implemented showed as Fig 10.1,Fig

10.2 and 10.3

Fig 10.1 Select the wavelength before you confirmed

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Fig 10.2 Select the wavelength after you confirmed

Fig 10.3 Blank automatically

Note: Pressing WL/Conc./F 【∧】,【∨】, the wavelength changes at 1nm ,

Pressing Menu Scroll 【∧】,【∨】,the wavelength changes at 20 nm interval.

3. Make a blank reference solution by filling a clean cuvette (or test tube) half full with

distilled or de-ionized water or other specified solvent. Wipe the cuvette with tissue to

remove the fingerprints and droplets of liquid.

4. Fit the blank cuvette into the 4-cell linear stage and place the cuvette in the slot nearest

you. Push the stage so that the cuvette is in the light path (Push the rod in). Close the lid.

5. Set 0.000A or 100%T with the (0A/100%T) control key.

6. Remove the blank cuvette if you are testing more than 3 samples. Set it aside in the case

that you may need to adjust the (0A/100%T) control key later (i.e. change the

wavelength).

7. Rinse a second cuvette (or more) with a small amount of the sample solution to be tested.

Fill the cuvette half full and wipe it.

8. Put the sample cuvette(s) in the sample compartment. Close the lid.

9. Read the % Transmittance and Absorbance from the LCD readout window. If you are

reading more than one cuvette, be sure to carefully move the stage to the next position by

pulling on the sample holder knob until you feel the holder “click” into place. Be sure to

make note of the readout (or print) for each sample. Remove the sample cuvette(s).

Operational Note:

a. if you are reading 3 or less samples, then place the reference cuvette in the position

nearest you, and the samples in the next available position. This will shorten the time to

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read samples and minimize the sample handling (opening and closing the sample

compartment lid, etc.)

b. If you are saving or printing the readings, please press PRINT/SAVE and follow the

instruction on line 4 of screen.

10. If you are to test the same sample at other wavelengths, repeat steps 2 to 10 for each

wavelength.

11. For each new sample you analyze, repeat steps 3 to 9.

Quantitative Test In Fig 7 Scroll * to Quantitative and then press ENTER to Select Quantitative Test

mode, showed as Fig 11.

Fig 11

Run test

Select Run Test in Fig 11 to enter a saved tests list shown as Fig 12.

Fig 12

Scroll * to the left of desired test and then press ENTER to confirm. Let’s take the “COBALT”

for example, the screen displayed as Fig 12.1, Fig 12.2 and Fig 12.3

Usually you should place the reference cuvette in the slot nearest you and place the sample

cuvette in the another slot, blank to reference by pressing 0Abs/100%T and take readings shown

as Fig 13 after putting the sample cuvette to light path.

Fig 12.1 goes to preset wavelength

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Fig 12.2 Blank automatically

Fig 12.3 After Blanking

Fig 13 Test result readings

NOTE: a. You can delete a test in Fig 12 by scrolling * to the left of its name and pressing

CLEAR/LOAD. Also you can add a test to the list in Fig 12, please refer to All Test

List.

b. If you are saving or printing the readings, please press PRINT/SAVE and follow the

instruction on line 4 of screen.

All Test List

Select All Test List in Fig 11 to enter ,All test list shown as Fig 14.

Fig 14

There are 200 un-defined tests listed in All Test List.

You can add a test in All Test List to Run Test menu by scrolling * to the left of its name

and pressing CLEAR/LOAD.

Note: You can’t run any test in All Test List, only in Run Test menu.

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Define a un-defined test in All Test List

The 200 un-defined tests are originally named “To be defined 001-200”,It will be possible to

rename the test by selecting wavelength, entering a new calibration and curve fitting option of

linear least squares or least squares through zero.

In Fig 14, scroll * to the left of desired to rename test and press ENTER to confirm, the Fig

15 appear. Let’s take “To be defined 02” for example:

Fig 15

If you have a calibrated test to define, please select “By Known Factors”. If you are

calibrating curve whose standard concentrations are between 1 and 8 data points, please select

“By Standard”.

By Known Factors

There are seven items for selection, shown as Fig 16.

Item1: Wavelength may be selected by pressing WL/Conc./F 【∧】,【∨】.

After confirm by pressing ENTER, screen return to previous menu and the * move to

item2 automatically.

Item2: Then concentration unit may be selected by pressing Menu Scroll 【∧】,【∨】.

After confirm by pressing ENTER, screen return to previous menu and the * move to

item 3 automatically.

Fig 16

Item3: Fitness method may be selected by pressing Menu Scroll 【∧】,【∨】.After

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confirm by pressing ENTER, screen return to previous menu and the * move to item4

automatically.

Item4: After ENTER is pressed, the screen displayed as Fig 17

Fig 17

On the assumption that the curve is expressed as:

Concentration = Intercept+ Slope*Absorbance; one order linear.

Concentration = Slope*Absorbance; one order linear through zero.

Let’s input Intercept=1.058

Press Menu Scroll【∨】to scroll right to number 1. Selection of number is controlled

by moving the flashing cursor over top of the number to be chosen. The Menu Scroll【∧】

scroll left. Press the Menu Scroll【∨】scroll right. Press WL/Conc./F 【∧】with the

flashing cursor over the number 1 to select it. The number 1 will appear now in line 3 next to =.

Continue in this fashion until entire 1.058 is entered. Showed as Fig 18

Fig 18

Press CLEAR/LOAD to delete/erase any incorrect entry.

Press WL/Conc./F 【∨】to alter the polarity of the number.

Press ENTER to finish entry and screen is displayed as Fig 19

Fig 19

Input Slope=2.588, the way is just like the entry of intercept.

After confirm by pressing ENTER, screen return to previous menu and the * move to item5

automatically.

Note: If you select “Liner through 0” in Item3, no intercept may be entered.

Item5: After ENTER is pressed, the screen displayed as Fig 20

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Fig 20

The entry of characters is the same as the entry of intercept and slope. After

BROMINE LR is entered, the screen is displayed as Fig21:

Fig 21

Press ENTER to go back to previous menu and the * move to item6 automatically.

Item6:The defined test/curve may be saved by pressing ENTER, after saved screen return to

previous menu and the * move to item7 automatically.

Item7:Pressing ENTER to display and print(if printer is connected) the test, the test number

(N0.=002),wavelength(581nm),test name(BROMINE LR), Fitness method(1 represent

“one order linear”, 2 represent“ one order linear through zero”, intercept(1.058),

slope(2.588) and concentration unit (ppm) are all included. Shown as Fig 22, any

incorrect entry may be checked with this item.

Fig 22

Note: Here N and M have no meaning.

Now all definitions to test 002 have been finished, press EXIT to return to All Test List

menu, the “To be defined 002” has been replaced with “BROMINRE LR ”. Shown as Fig

23.

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Fig 23

By Standard

There are nine items for selection, shown as Fig 24.

Item1: The same operation as in By Known Factors;


Item3: Selection of how many data points which be used for standard curve establishing,

the maximum is eight points.

Item4: Selection of how many times measurement to one standard concentration sample;


Fig 24

Item6: After Measure Standard is selected, the screen is displayed as Fig 25

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Fig 25

Place reference solution cuvette in sample compartment, press 【0Abs/100%T】. The Fig

26 appears after the Blank finishes;

Fig 26

On the assumption that 3 standard solution (data points) are measuring. Place all 3 sample

solution cuvettes in compartment and pull standard solution No.1 to light path.

Enter the value of standard solution No.1 like the operation of intercept Entry in By Known

Factors. Press ENTER, the Absorbance vs. Standard solution No.1 will be measured and

displayed as Fig 27.

Fig 27

If you set the replicas, No=3 in item4, Press ENTER second time, standard solution No.1

will be measured again and the screen display 0.18775A2,press ENTER third time, display as

0.1876A3,press ENTER fourth time, display as 0.1876A, so we have get the Absorbance vs.

Standard solution No.1 0.1876A that is from (0.1877A1+0.1875A2+0.1876A3)/3.

If you have 3 standard solutions available, please pull standard solution No.2 and No.3 to light

path. Repeat the operation above; after you finish measurement to all 3 standard solution, the

screen is displayed as Fig 28.

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Fig 28

After pressing ENTER, the screen goes back to previous menu,

Note: You may view the created curve in Item 9 (Dis. & Print Curve)




UTILITY

A few specific functions can be set in UTILITY menu.

In MAIN MENU (Fig 7), move * down to the left of UTILITY and press ENTER to go into

UTILITY menu, shown as Fig 29

Fig 29

There are 9 items listed in UTILITY menu.

Wavelength Calibration

Item1: After selecting WL Calibration, the instrument will implement a self testing procedure; it

contains filter locating check, lamp locating check and wavelength calibrating.

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Collecting Dark Current

Item2: Dark Current is designed to eliminate the error from the light source and electronic parts

drifting. It is recommended that you refresh and save the Dark Current by selecting this

Item after 15 minutes warm up;

Edit Clock

Item3: In Edit Clock menu, there 3 sub-items are listed, Fig 30.

Set Clock

Select Set Clock in Fig 30, displayed as Fig31. If any require changing, press ENTER to

cycle through Set Week, Set Year, Set Month, Set Day, Set Hour, Set Minute, Set Second, until

required one is displayed on Line3. Press WL/Conc./F 【∧】【∨】to change. Press ENTER to

confirm. Press EXIT back to Fig 30.

Fig 30

Fig 31

Select Display of Date or Time

Select Display Mode in Fig 30, displayed as Fig32. Press Menu Scroll 【∧】【∨】to

select Display Time or Display Date. Press ENTER to confirm. Press EXIT back to Fig 30.

Fig 32

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System Baseline

Item4: System Baseline is used for determining the appropriate energy level which cover all

wavelength range 324vnm to 1000vnm for Alpah-1101 and Alpha-1102 and 204 nm to

1000 nm for Alpha-1502. Fig 34 shows the procedure of establishing system baseline.

Fig 34

Turn on/off Deuterium Lamp

Item5: Turn on/off D2 The deuterium lamp (D2)energy decreases with time, so if wavelength

200 to 340 are not being used, it is advisable to turn off deuterium lamp. This item is

designed for this demand.

Turn on/off Tungsten Halogen Lamp

Item6: Turn on/off Tungsten Halogen Lamp. The Tungsten Halogen lamp (W) energy decreases

with time, so if wavelength 340 to 1000 are not being used, it is advisable to turn off

deuterium lamp. This item is designed for this demand.

Reset Defaults

Item7: Reset Defaults is designed for future application;

Memory Manager

Item8: Select Memory Manager to go into next screen, shown as Fig 35. There are 3 sub-items

listed.

Fig 35

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Load Saved data

Select Load Saved data in Fig 35, the saved data will list all as Fig36.

Fig 36

With * next to COBALT, press ENTER, you can print the data (if printer installed) and display it

on screen, or you can send the data to computer shown as Fig 37.

Fig 37

Clear User Tests

Select Clear User Tests in Fig 35, all established and saved tests/curves will be deleted.

Please be careful for this choice.

Clear Data Memory

Select Clear Data Memory in Fig. 35. All saved tests data will be deleted. Please be careful

for this choice.

Wavelength Correction

Item9: If, after WL Calibration, it is found that the holmium specific peak is not in the correct

position, this item can be used to change it. Select WL Correction in Fig 29 to go into Fig

38.

Fig 38

Press WL/Conc./F 【∧】【∨】to make choice.

Press ENTER to confirm.

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Press EXIT back to previous menu.

Note: WL Correction was done at the factory. It is not recommended for customer to do it.

The corrected WL will be saved in memory and will be held after power off.

PC LINK

Alpha-1101, Alpha-1102 and Alpha-1502 are designed to be operated by Computer with

the application software. In fig 7, move * to the left of PC LINK and press ENTER, the screen is

displayed as Fig 39.

Fig 39

After it finishes handshaking with PC, the screen is displayed as Fig 40. Please refer to the

application software manual for detailed.

Fig 40

Wavelength Calibration:

Normally, the Alpha-1101, Alpha-1102 and Alpha-1502 Series spectrophotometer retains its

wavelength calibration indefinitely. However if the instrument receives a severe shock or is

abused, use the following methods to check wavelength calibration. Please note that this test

requires the use of a Didymium filter, or the Holmium Oxide filter.

In the filter method, the didymium filter has two distinct absorbance peaks at 529nm and 807nm.

The Holmium filter has a distinct peak at 361nm. When the instrument is calibrated properly

you will find minimum Transmittance (maximum Absorbance) at the range +2nm from these

peaks. Note that the specific Transmittance values are not important as you are only looking for

the wavelength where the minimum transmittance (maximum Absorbance) occurs.

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Holmium Oxide Filter Method:

1. Turn instrument on and allow it to warm up for 15 minutes.

2. Select the BASIC MODE.

3. Set the wavelength to 350nm.

4. Make sure the cuvette holder is empty in the sample compartment. Close the sample

compartment lid.

5. Set zero Absorbance by pressing the 0A/100%T. The reading should then be 0.000A. If not,

press 0Abs/100%T again.

6. Remove the cuvette holder and insert the Holmium filter into it. Place it in the sample

compartment and close the lid.

7. Record the Absorbance reading on the LCD display.

8. Advance the wavelength setting by 1nm and repeat steps 2 to 5.

9. Repeat step 6 until the wavelength setting reaches 370nm.

10. Look for the maximum absorbance reading obtained, and this should be found between 359

and 363nm.

Didymium Filter Method:

1. Set the Wavelength to 800 nm.

2. Make sure the cuvette holder is empty in the sample compartment. Close the sample

compartment lid.

3. Set zero Abs by pressing the 0A/100%T. The reading should then be 0.000A. If not, press

0Abs/100%T again.

4. Remove the cuvette holder and insert the Didymium filter into it. Place it in the sample


5. Record the Absorbance reading on the LCD display.


7. Repeat step 6 until the wavelength setting reaches 815nm.

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8. Look for the maximum absorbance reading obtained, and this should be found between 805

and 809nm.

9. If a “middle” wavelength check is desired, set the wavelength to 522nm (optional)

10. Make sure the cuvette holder is empty in the sample compartment. Close the sample lid.

11. Set zero Abs by pressing the 0A/100%T key. The reading should then be 0.000A .If not,

press 0Abs/100%T again

12. Remove the cuvette holder and insert the Didymium filter into it. Place it in the sample


13. Record the absorbance reading on the LCD display.


15. Repeat step 14 until the wavelength setting reaches 536nm. Again, look for the maximum

absorbance reading. It should be between 527 and 531nm.

Absorbance Accuracy Checks

Specification: +0.004A at 0.5A.

The absorbance accuracy should be checked against a set of neutral density filters accurately

calibrated to the NIST standards. Contact your factory representative for more information.

An alternative method using potassium dichromate is described below. Due to the many factors

that might affect the results (i.e. temperature, band pass, weighing and diluting errors), this

method is less accurate and should only be used as a guide.

1. Make up N/100 sulfuric acid as the solvent and use part of it to make a solution

containing 120 +0.5mg/liter of potassium dichromate.

2. Wash out a square cuvette with solvent, and fill with solvent.

3. Put the cuvette into the sample compartment and close the lid.

4. Select BASIC MODE and Set the wavelength to 350nm.

5. Set the reading to 0.000A using the 0Abs/100%T key.

6. Empty the cell. Wash out with dichromate solution, and fill with dichromate solution.

7. Put the cuvette into the sample compartment and close the lid.

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8. Read the absorbance of the standard from the LCD display. The value should be

Calibrated Value + 0.004A. Refer to the notes above when interpreting the result.

Note: It is recommended that you refresh the Dark Current setting (refer to Page19).

Stray Light Check

Specification: ≤ 0.1%T at 360 nm and 400 nm (Alpha-1101,1102); ≤0.1 %T at 220 and 340 nm

(Alpha-1502)

A good indication as to whether the stray light level is within specification may be obtained as

follows:

1. Set the wavelength to 340nm.

2. Select BASIC MODE with the sample compartment empty, close the lid and press the

0A/100%T key to set the LCD display to 100.0%.

3. Prepare a solution containing 50gm/L of sodium nitrite (NaNO2) in distilled water and fill

a square cuvette with this solution.

4. Place the cuvette in the sample compartment. Close the lid. The display should read

≤0.1%T.

Note: It is recommended that you refresh the Dark Current setting (refer to Page19).

Trouble Shooting:

PROBLEM Possible Solution

Instrument Inoperative Power cord not connected to

outlet

Plug instrument in.

Dead Power outlet Change to a different outlet

Internal fuse blown or

defective electronic component

Call an authorized service engineer.

Improper power setting Set to the main power

Instrument cannot set

100%T (0.000A)

Light beam blocked Check sample holder. See if holder is

properly positioned and nothing is blocking

light path.

Lamp is misaligned. Check to see if light is positioned properly on

entrance slit to monochromator. Call

Technical Service for details.

Defective electronic

component.


Incorrect

Transmittance to

Bubbles or particles in

solution.

Check sample preparation and analytical

procedure.

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Absorbance correlation


component.


LCD Digital Display

does not change

regardless of sample

concentration

Concentration reading

“frozen”.

Sample Solution too Dark , dilute it and

Restart measurement procedure.

Wrong wavelength setting. Check sample procedure and wavelength

setting.

Insufficient sample volume. Fill cuvette with more sample.

Stray sample preparation

vapors.

Prepare the sample away from the

instrument. Use proper ventilation.


solution.


procedure.


component or loose wiring.


Instrument drift and

noise

Lamp not adjusted properly. Check lamp has been properly installed or

has moved during transit.

Lamp old or defective. Replace with a new lamp.

Defective or dirty detector or

defective electronic

component.


Incorrect readings

obtained

Insufficient sample volume Fill cuvette with more sample.

Wrong wavelength setting. Check analytical procedure and wavelength

setting. Check wavelength accuracy

according to procedure in this manual.

Stray sample preparation

vapors.

Prepare sample away from instrument. Use

proper ventilation.


solution.


procedure.

Instrument out of electronic

calibration.


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Error Codes Definitions:

The Error Codes are the classification for errors detected automatically by the instrument. Each code

represents different errors that occur during the self-calibration or during operation. The Error Codes are

displayed on the wavelength display and are defined as follows:

Error Code Definition (function) Causes/Solutions

Error 1 Instrument unable to

initialize and/or locate the

lamp (Alpha-1502only).

Check power supply to see if proper voltage is

selected.

Open cover of instrument and check the connector

J12 between CPU board and Lamp-change-over

motor .

Lamp-change-over motor or lamp initialization

switch malfunctioning. Check the connector J13 on

CPU board.

Call authorized service engineer

Error 2 Instrument unable to

initialize and/or locate the

filter

Open cover roof instrument and check the connector

J4 between CPU board and Filter-driven motor.

Filter-driven motor malfunctioning. Check the

connector J2 on CPU board.

Call authorized service engineer

Error 3 Monochromator unable to

locate starting position Monochromator contact switch or grating-driven

motor (WL motor) is malfunctioning

Open cover of instrument and check the connector J3

between CPU board and grating-driven motor.

Check the connector J5 on CPU board

Call authorized service engineer.

Error 4 Instrument unable to locate

“0” order light

Check sample holder. See if holder is properly

positioned and nothing is blocking light path.

Check to see if light is positioned properly on

entrance slit to monochromator.

Check tungsten-halogen lamp. Replace lamp if

necessary.

Call authorized service engineer.

Error 5 Instrument is unable to set

0A/100%T.“Energy

Low!” display.

Check sample compartment and remove cuvette or

any object blocking light path.

Place the 4-cell sample holder in the proper position.

See if the lamps is ON or OFF via the small hole in

the rear of the instrument. If OFF, call authorized

service engineer.

Contact an authorized service engineer.

Documents

SPECTROPHOTOMETER OPERATONAL MANUAL V 1.0 Revision 1