Operating the Spectronic 20 Genesys Spectrometer
Last Update: June 27, 2013
Basic Set Up
The instrument is shown in Fig. 1. Before attempting any measurements, the instrument must be turned on (switch is located on the back near the power cord) and allowed to warm up for at least 10 minutes. When switched on, the instrument will display various messages and perform several self-tests. If the power-up is successful, the default wavelength and the uncalibrated absorbance at that wavelength will be displayed.
Figure 1. Spectronic 20 Genesys spectrometer.
Operation
The keypad for the Genesys is shown in Fig. 2. For simple absorbance measurements, only three keys are used (two to adjust the wavelength and one to set the blank). The control keys and their function are summarized in Table 1.
Figure 2. The Spectronic 20 Genesys control pad.
| Key | Function |
|---|---|
 | Decreases the measurement wavelength. |
 | Increases the measurement wavelength. |
 | Sets the absorbance to 0 or the %transmittance to 100% at the current wavelength. |
 | Toggles between Absorbance, %Transmittance and Concentration measurement modes. |
 | Allows the user to set various default parameters. There is no need to use this key for routine operations. |
 | Print the results. This key is not functional on our instruments because we have no printer. |
 | Used to set the absorbance at a specific wavelength. Should not be used for routine measurements. If you accidentally press one of the arrow keys, which will activate this mode, simply press the left key (the word Esc will be shown in the display directly above it) to exit. |
Once the spectrometer has warmed up, set the wavelength using the keypad. Open the hinged sample compartment (on the lower right side of the instrument) and place a cuvette containing your blank in the sample holder (shown in Fig. 3). Be sure that you have wiped the cuvette carefully with a Kimwipe to remove any drops of solution or other contaminants from the outside of the cuvette before placing it in the sample holder. Close the sample compartment door and press the 0 ABS/100% T button to blank the spectrometer at your chosen wavelength. The display will read 0.000 A (or 100.0 T). If not, press to blank button again.Table 1. Spectronic 20 Genesys keys and their functions.
Figure 3. Enlarged view of the Genesys’ sample compartment showing the sample holder. The light path is from the back of the instrument to the front (top to bottom in this view) as indicated by the arrow on the right side of the sample holder.
You are now ready to make an absorbance measurement on your sample. Simply fill the cuvette with the sample, wipe down the sides and place it in the sample holder. Close the sample compartment door and read the absorbance at your chosen wavelength from the display.
You can continue to make measurements at this wavelength without re-blanking the instrument (although it is a good idea to re-blank the instrument from time to time to account for any baseline drift). However, if you change the wavelength then you will need to re-blank the spectrometer at the new wavelength.
Shutdown
To shut the instrument down, simply remove the sample from the sample holder and turn the power switch to the “off” position.