UNITED PRODUCTS & INSTRUMENTS INC. UNICO 1100 User manual

UNICO 1100 SERIES
SPECTROPHOTOMETER
Model 1100 Spectrophotometer
Model 1100RS Spectrophotometer
SERVICE MANUAL
UNITED PRODUCTS & INSTRUMENTS INC.
•
MANUFACTURER OF QUALITY OPTICAL SYSTEMS

CONTENTS
1. GENERAL 3
1.1 Introduction 3
1.2 Optical System 4
1.3 Electronic 5
1.4 Specifications 6
1.5 Nomenclature 6-7
2. INSTALLATION 7
3. MAINTENANCE 8
3.1 orking Environment 8
3.2 Replacing Lamps And Adjustments 8
3.3 avelength Calibration 8-9
4. SER ICE 9
4.1 Operating Procedure Check 9-10
4.2 Physical 10
4.3 Troubleshooting 11-19
5. DRAWING AND DIAGRAM 20
5.1 PCB Arrangement of Synthetic Electronic System for UNICO 1100 21
5.1.1 Circuit Diagram of Synthetic Electronic System for UNICO 1100 22
5.2 PCB Arrangement of ± 15v, + 9v Power Supply 23
5.2.1 Circuit Diagram of ± 15v, + 9v Power Supply 24
5.3 PCB Arrangement of Lamp Power Supply 25
5.3.1 Circuit Diagram of Lamp Power Supply 26
5.4 PCB Arrangement of Logarithm Adjustment 27
5.4.1 Circuit Diagram of Logarithm Adjustment 28
5.5 PCB Arrangement of 0%T Adjustment 29
5.5.1 Circuit Diagram of 0%T Adjustment 30
5.6 PCB Arrangement of Amplifier 31
5.6.1 Circuit Diagram of Amplifier 32
6. SCHEMATIC LOYOUT 33
6.1 Schematic Diagram of UNICO 34
7. ELECTRONIC PARTS FOR UNICO 1100 35
7.1 Electronic Parts list for UNICO 1100 35
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1. GENERAL
1.1 INTRODUCTION
The UNICO model 1100 Series spectrophotometers are single beam
general purpose instruments designed for use in conventional laboratories.
The instruments are ideal for various applications such as: Clinical
Chemistries Biochemistry Food and Beverage Laboratories Environmental
Protection Water and Waste Water Labs and other fields of quality control.
The UNICO 1100 Series spectrophotometers cover the visible
wavelength range from 335nm to 1000nm. The analytical grating system has
1200 lines/mm for higher dispersion of the spectrum.
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Figure 1-1.1
UNICO Model 1100 Spectrophotometer
Figure 1-1.2
UNICO Model 1100RS Spectrophotometer
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1.2 OPTICAL SYSTEM
As shown in Figure 1-2 the white light coming from the Halogen Lamp is
focused by the collecting lens pass through the Entrance slit of the
Monochromator through a collimating lens to the Analytical grating where it is
dispersed into its spectrum then through the Exit slit of the monochromator
continues through the Sample compartment and finally to the Photo detector.
Figure 1-2
OPTICAL SYSTEM SCHEMATIC DIAGRAM
1. Halogen Lamp 2. Collecting Lens
3. Entrance Slit 4. Collimating Lens
5. Grating 6. Exit Slit
7. Sample 8. Collimating Lens
9. Photodiode
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1.3 ELECTRONIC SYSTEM
The photo detector receives the monochromatic light and generates
photocurrent. A direct current signal which is proportional to the amount of
light energy to the photo detector. The signal is then amplified and processed.
The processed signal is sent to the digital display and also to the external
outputs 0 Volt to 1 Volt analog output and an RS-232C output. Figure 1-3-1
and Figure 1-3-2 demonstrates the electronic systems of Model 1100 and
Model 1100RS respectively
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1.4 SPECIFICATIONS
Table 1-1
MODEL 1100 1100RS
Wavelength Range 335-1000nm 335-1000nm
Spectral Slit Width 20nm 10nm
Wavelength Accurac
±2nm
±2nm
Wavelength Readabilit 2nm
Stra Radiant Energ
≤0.5%T@340nm &400nm
≤0.5%T@340nm & 400nm
Transmittance 0%T to 125%T 0%T to 125.0%T
Absorbanc 0A to 2A 0A to 2A
Photometric Accurac ±2.0%T ±1.0%T
Photometric Noise Level
±2.0%T
±1%T
Power Requirement 115-volt, 60Hz, or 230-volt, 50Hz
Size
408mm(W)×308mm(D)×180mm(H)
Weight 5.5kg
Specifications subject to change without notice
1.5 NOMENCLATURE
Figure 1- 4
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Figure 1- 5
UNICO 1100 SPECTROPHOTOMETER AND NOMENCLATURE
2. INSTALLATION
2.1 The instrument should be installed in a clean environment which is free of
corrosive materials dust and severe vibrations. Furthermore it should be
kept away from any strong electric magnetic fields and high frequency fields.
2.2 LINE OLTAGE
The power can be selected by means of the built-in switchable power
switch to match the line voltage in your country.
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3. MAINTENANCE
3.1 WORKING EN IRONMENT
The optimum environment for the instruments is as follows
TEMPERATURE 5-35 ° C
HUMIDITY 85%
Install the instrument in a clean non-vibrational area. Avoid direct strong
light and air flow. The instrument will give better performance if the power
supply stability is at 1% and line frequency less than 1Hz. Always allow the
instrument to warm up for 20 minutes prior to taking any readings.
3.2 REPLACING LAMPS AND ADJUSTMENTS
1. Turn off and unplug the instrument.
2. Turn the instrument upside down.
3. Remove the grill plate on bottom of the instrument by removing fixing
Screw.
4. Unplug the lamp from the white connector.
5. Insert the new lamp pushing it in as far as it will go. The lamp filament
should face the center of the collecting lens.
CAUTION: DO NOT HANDLE HALOGEN LAMP ITH BARK FINGERS. USE TISSUE OR CLOTH
HEN HANDLING LAMP.
8. Reinstall the grill plate.
Figure 3-1
Replacing the lamp
3.3 Wa v e l e n g t h Cali b r a t i o n :
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Normally the UNICO 1100 Series spectrophotometer retains its wavelength calibration
indefinitely. However if the instr ment receives a severe shock or is ab sed, se the
following methods to check wavelength calibration. Please note that this test req ires the
UNICO Didymi m filter, p/n 1100-110, or the Holmi m Oxide filter, p/n 1100-109.
In the filter method, the didymi m filter has two distinct absorbance peaks at 529nm
and 807nm. The Holmi m filter has a distinct peak at 361nm. When the instr ment is
calibrated properly yo will find minim m Transmittance (maxim m Absorbance) at the range
+2nm from these peaks. Note that the specific Transmittance val es are not important as yo
are only looking for the wavelength where the minim m transmittance (maxim m
Absorbance) occ rs.
Holmium Oxide Filter Method:
1. T rn instr ment on and allow it to warm p for 15 min tes.
2. Select the Absorbance operating mode.
1. Set the wavelength to 350nm.
2. Make s re the c vette holder is empty and place it in the sample compartment. Close
the sample compartment lid.
3. Set zero Absorbance by pressing the 0A/100%T. Wait a few seconds while the display
flashes ‘BLA’. The reading sho ld then be 0.000A. If not, repeat step 5.
4. Remove the c vette holder and insert the Holmi m filter into it. Place it in the sample
compartment and close the lid.
5. Record the Absorbance reading on the digital display.
6. Advance the wavelength setting by 1nm and repeat steps 4 to 7.
7. Repeat step 8 ntil the wavelength setting reaches 370nm.
8. Look for the maxim m absorbance reading obtained, and this sho ld be fo nd between
359 and 363nm. The wavelength acc racy of the 1100/1100RS is + 2nm.
Didymium Filter Method:
1. Set the Wavelength to 800 nm.
2. Make s re the c vette holder is empty and place it in the sample compartment. Close
the sample compartment lid.
3. Set zero Abs by pressing the 0A/100%T. Wait a few seconds while the display flashes
‘BLA’. The reading sho ld then be 0.000A. If not, repeat step 3.
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4. Remove the c vette holder and insert the Didymi m filter into it. Place it in the sample
compartment and close the lid.
5. Record the Absorbance reading on the digital display.
6. Advance the wavelength setting by 1nm and repeat steps 2 to 5.
7. Repeat step 6 ntil the wavelength setting reaches 815nm.
8. Look for the maxim m absorbance reading obtained, and this sho ld be fo nd between
805 and 809nm. The wavelength acc racy of the 1100/1100RS is + 2nm.
9. If a “middle” wavelength check is desired, set the wavelength to 522nm (optional)
10. Make s re the c vette holder is empty and place it in the sample compartment. Close
the sample lid.
11. Set zero Abs by pressing the 0A/100%T b tton. Wait a few seconds while the display
flashes ‘BLA’. The reading sho ld then be 0.000A. If not repeat step 11.
12. Remove the c vette holder and insert the Didymi m filter into it. Place it in the sample
compartment and close the lid.
13. Record the absorbance reading on the digital display.
14. Advance the wavelength setting by 1nm and repeat steps 10 to 13.
Repeat step 14 ntil the wavelength setting reaches 536nm. Again, look for the maxim m
absorbance reading. It sho ld be between 527 and 531nm.
Absorbance Accuracy Checks
Specification: +2% at 1A (1100), +1% at 1A and 2A (1100RS).
The absorbance acc racy sho ld be checked against a set of ne tral density filters
acc rately calibrated to the NIST standards. Contact yo r UNICO representative for more
information (800-588-9776).
An alternative method sing potassi m dichromate is described below. D e to the many
factors that might affect the res lts (i.e. temperat re, bandpass, weighing and dil ting errors),
this method is less acc rate and sho ld only be sed as a g ide.
Reference: Johnson E A
Potassi m Dichromate as an absorbance standard
PSG B lletin 1967, No. 17, page 505
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1. Make p N/100 s lf ric acid as the solvent and se part of it to make a sol tion
containing 120 +0.5mg/litre of potassi m dichromate.
2. Wash o t a sq are c vette with solvent, and fill with solvent.
3. P t the c vette in the adapter into the sample compartment and close the lid.
4. Set the wavelength to 350nm.
5. Set the MODE b tton to A.
6. Set the reading to 0.000A sing the 0A/100%T b tton.
7. Empty the cell. Wash o t with dichromate sol tion, and fill with dichromate sol tion.
8. P t the c vette in the adapter into the sample compartment and close the lid.
9. Read the absorbance of the standard from the display. The val e sho ld be 1.288 +
0.04A. Refer to the notes above when interpreting the res lt.
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Stray Light Check
Specification: Less than 0.5%T at 340nm by ASTM E 387
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. Set the MODE switch to %T.
3. With the sq are cell adapter in the sample compartment, b t no cell, close the lid
and press the 0A/100%T b tton to set the display to 100.0%.
4. Remove the cell adapter from the sample compartment and close the lid. Make a
note of the reading that sho ld be at or near 00.0.
5. Prepare a sol tion containing 50gm/L of sodi m nitrite (NaNO2) in distilled water and
fill a sq are c vette with this sol tion.
6. Insert the c vette into the adapter and place in the sample compartment. Close the
lid. The display sho ld read<0.5%T. Note that if the reading obtained in step 4 is
greater than 00.0, this val e sho ld be s btracted from the displayed reading to give
the correct reading for the stray light val e.
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SERI CE
4.1 PHYSICAL INSPECTION
Thoroughly inspect the instrument for physical indications that might cause a
malfunction. The following categories are usually checked:
Apparent damage Dirty Optics Broken wire loose connection P.C. Board
loose Broken lands on pc board any sign of overheated components.
4.2 OPERATING PROCEDURE CHECK
Each time an instrument has a malfunction the operating procedure should
be checked. If necessary such procedures should be repeated to see the
patterns that the malfunction occurs.
The basic operating procedure is as follows:
Basi c Ope r a t i o n :
Simple operating instr ctions are printed on the front panel of yo r UNICO 1100/1100RS.
A. Pre p a r e the spec t r o p h o t o m e t e r
1. T rn on the spectrophotometer by pressing the Power Switch (IO). Allow 15 min tes
for the instr ment to warm p.
2. Select either the %Transmittance or Absorbance operating mode by pressing the
%T/A selector b tton (MODE) ntil the red light for T or A is on.
3. Select the desired wavelength by t rning the wavelength control knob
(WAVELENGTH).
B. Pre p a r e Sa m p l e
4. Make a blank reference sol tion by filling a clean c vette (or test t be) half f ll with
distilled or de-ionized water or other specified solvent. Wipe the c vette with tiss e
to remove the fingerprints and droplets of liq id.
5. Fit the blank c vette into the sq are c vette adapter and place the adapter in the
sample compartment, aligning the g ide mark (if present) with the g ide mark at the
front of the compartment. Close the lid.
6. Set 0.000A or 100%T with the (0A/100%T) control b tton. NOTE: This step f lfills
the instr ction on the front of the spectrophotometer…(Set F ll Scale).
7. Remove the blank c vette or test t be. Set it aside in the case that yo may need to
adj st the (0A/100%T) control b tton later (i.e. change the wavelength).
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C. A n a l y z e Sa m p l e
8. Rinse a second c vette with a small amo nt of the sample sol tion to be tested. Fill
the c vette half f ll and wipe it.
9. P t the sample c vette in the sample compartment. Close the lid.
10. Read the %Transmittance or Absorbance from the digital reado t window. Remove
the sample c vette or test t be.
11. If yo are to test the same sample at other wavelengths, repeat steps 3 to 10 for
each wavelength.
12. For each new sample yo analyze, repeat steps 2 to 11.
A d d i t i o n a l Feat r e s of Mo del 11 0 0 R S
Altho gh operating basically the same as the Model 1100, the 1100RS spectrophotometer
offers two more feat res (Concentration Mode and Factor Mode) as follows:
Concentration (C) Mode for determining the concentration of
unknown samples.
NOTE: This method should only be used when the relationship between Absorbance and
Concentration is known to be linear. The concentration o the Standard solution used to
calibrate the instrument should be higher than the most concentrated sample.
1. Select the desired wavelength by t rning the wavelength control knob.
2. Using the MODE b tton, select Absorbance (A) mode.
3. Insert the c vette containing the blank sol tion.
4. Set 0.000A with the (0A/100%T) control b tton.
5. Using the MODE b tton, select C (concentration) mode.
6. Insert a c vette containing a standard sol tion of known concentration in the sample
compartment and adj st the digital reado t window to the val e of the standard by sing
the ∧ and ∨ arrows.
7. Press the Enter b tton.
NOTE: I the reading changes, the actor required is too high (i.e. >1999) to be displayed. In
this case, divide the concentration by 10, re- select the C mode by successive presses on the
Mode button, cycling through the F, %T, and A modes, and ollow step 2 above to set the
concentration o the standard to the reduced value.
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8. With the standard concentration set, determine the concentration val es of samples with
nknown concentration by inserting the sample c vette into the sample compartment
and reading the val e direct from the display.
9. To read the val e of the m ltiplier sed to convert Abs to Concentration, after meas ring
all the samples, change the Mode to Factor (F) and read the m ltiplier from the display.
Keep a record of this val e for f t re se.
Operational Note: i the mode switch is changed to read Factor or Absorbance, the
Concentration (C) reading is “ rozen”, and cannot be changed. This requires the operator to
re-start at step 1.
Facto r (F) Mode
This is a special mode for meas ring concentration val es of nknown samples sing a
previo sly determined factor to convert Absorbance readings to concentration.
1. After setting the wavelength, and setting zero Abs on the blank sol tion, sing the
MODE b tton, select factor (F) mode.
2. Insert a c vette containing a sample.
3. Using the ∧and ∨ arrows, set the digital read-o t window to the desired val e of the
m ltiplier.
4. Press the ENT b tton. The spectrophotometer switches to the Concentration (C)
MODE.
Operational Note: I the Concentration o the sample is too high to be displayed, the
instrument will not switch to Concentration Mode when the ENT button is pressed. Dilute the
sample and multiply the concentration reading by the dilution actor to obtain the original
sample concentration.
5. Read the concentration val e of the sample direct from the display.
6. Insert a c vette containing the next sample and read the res lt. Repeat ntil all
samples have been meas red.
Operational Note: I the MODE switch is changed to A or T, then the concentration reading is
“ rozen”. This requires the operator to re- start at step 1.
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Mode l 11 0 0 Spect r o p h o t o m e t e r :
Mode Indicator: Allows the operator to know the measurement mode currently in use
(%Transmittance, Absorbance) .
MODE B tton: Switches between %Transmittance and Absorbance operating modes at any
time o measurement.
0A/100%T B tton: Adjusts digital readout to 100%T or 0.000A when blank re erence solution
is in sample compartment.
Sample Compartment: Insert 10mm test tube and close lid or it 10mm cuvette adapter and
it adapter (with holder to le t o cuvette) into compartment.
Wavelength Control Knob (WAVELENGTH): Selects desired wavelength in nanometers
(nm).
Wavelength Reado t Window: Displays desired wavelength.
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Mode l 11 0 0 R S Spect r o p h o t o m e t e r :
Mode Indicator: Allows the operator to know the measurement mode currently in use
(%Transmittance, Absorbance).
MODE B tton: Switches between %Transmittance and Absorbance operating modes at any
time o measurement.
0A/100%T B tton: Adjusts digital readout to 100%T or 0.000A when blank re erence solution
is in sample compartment.
0%T B tton: When in transmittance (T) mode and sample compartment is empty, a lap
blocks the beam. Pressing button adjusts readout to 00.0%T.
PRINT B tton (ENT): First press a ter selecting Concentration mode enters reading on digital
readout. Other presses cause output o reading to printer. I using UNICO Application
So tware, press this button to communicate with so tware. I operating in Factor (F) Mode,
then press to enter actor. This causes the Mode to enter the actor number and change to
Concentration mode.
Sample Compartment: Insert 10mm test tube and close lid or it 10mm cuvette adapter and
it adapter (with holder to le t o cuvette) into compartment.
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