Spectronic 20+ Series User Manual

SPECTRONIC 2ar series
10.
Fill a IOmrn pathlength rectangular cuvette with
O.OIN sulfuric acid solution and place it in the
sample compartment.11.
Set the: readout of the instrument to OA.12.
Fill the IOmm pathlength rectangular cuvette with
O.O25g/L potassium dichromate solution, place it
in the sample compartment and read the
absorbance. You should expect to read O.248A.13.
Fill the IOmm pathlength rectangular cuvette with
O.O5g/L potassium dichromate solution, place it in
the sample compartment and read the absorbance.
You should expect to read O.496A.
To change the phototube:
1. Turn ofT and unplug the instrument.
2. Tilt up the unit and set on its back.
3. Loosen the thumbscrew on the lamp access door
(see Figure 1-3).
4. Remove the phototube using the plastic straps as an
aid (see Figure 3-3).
Values should be within O.O2A of the
expected absorbance values, if the solutions
have been prepared carefully.
Note:
~ Do not touch the lamp with your fingers!
Replacing phototubes (SPECTRONIC~ 20 or20D
models only)
5. Install the new phototube. If a filter is required,
insert it into the holder on the inside of the door (see
Figure 3-3). The tube and filter must be clean and
free of fingerprints, (If necessary, use a lint-free
tissue for cleaning.)
6. Close the door and securely fasten the thumbscrew.
This is essential for proper operation.
4 The lamp and surrounding metal parts get
~ very hot during operation. Before
removing the phototube, turn off the instrument
and allow the area to cool down for 10 minutes.

Spectronic 20+ Series Specifications

General

Spectral Bandwidth	20 nm
Light Source	Tungsten lamp
Detector	Silicon photodiode
Wavelength Accuracy	±2 nm
Display	Digital display (Spectronic 20+)
Power Requirements	50/60 Hz
Sample Holder	Accommodates standard 10 mm square cuvettes