Unico SQ Series, Service Manual, Page: 90 / 96

Maintenance
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1. Prepare (Refer 7.6.1).
2. Press 3 to select “WL Scan”, press “F1” to setup, set the parameter as
follow, press “Enter” to finished setup.
Scan from: 400
Scan to: 300
Scan Step: 0.1
Scan Speed: HI
3. Ensure beam is clear. Press “0Abs” to scan blank.
4. Insert holmium filter. Press “Start”.
5. When scan complete, press “F3”: Search, Press “
▼ ”, record wavelength
of holmium peak (specification: 360.9 ±1nm).
6. Press “ESC”, press “F1” to setup, set the parameter as follow, press
“Enter” to finished setup.
Scan from: 850
Scan to: 750
Scan Step: 0.1
Scan Speed: HI
7. Ensure beam is clear. Press “0Abs” to scan blank.
8. Insert didymium filter. Press “Start”.
9. When scan complete, press “F3”: Search, Press “
▼ ”, record wavelength
of didymium peak (specification: 807.1 ±1nm).
7.6.3 Check Stray Light
1. Prepare (Refer 7.6.1).
2. Press “Set
λ
”, input 340, press “Enter” to go to 340nm.
3. Ensure beam is clear. Press 1 to “Basic Mode” and automatic blanking.
4. Insert GG375 filter.
5. Record stray light at 340nm (specification >3A, <0.1%T).
6. Remove
filter.
7. Press “Set
λ
”, input 220, press “Enter” to go to 220nm.
8. Insert WG295 filter.
9. Record stray light at 220nm (specification >3A, <0.1%T).
7.6.4 Check Absorbance Accuracy
1. Prepare (Refer 7.6.1).
2. Fit neutral density filters, blank, 0.5A, 1A, 2A in cell changer and move
blank into beam
3. Press “Set
λ
”, input 546, press “Enter” to go to 546nm.
4. Push filters into beam and record values. Compare the results with the
calibrated absorbance (specification <±1%A, so <±0.005A at 0.5A,
<±0.010A at 1A, <±0.020A at 2A).