Bio-Rad VersaFluor™ Fluorometer User Manual

Page 22

2. The three right-hand push buttons are used to operate the diagnostics. Starting from the

right, the first push button turns the lamp on or off, the second selects the voltage to be
inserted into the instrument, and the third selects the amplifier gain. The diagnostics are
restricted to testing the analog electronics and digital processing, which includes post
amplification, gain changes, A/D conversion, digital filtering, and the LCD display. One
of three fixed voltages is inserted into the analog amplifiers just following the photodiode
(PD) detector and preamplifier.

3. Two different values can be changed through the diagnostic routines: the voltage setting

and the gain setting of the analog amplifier. The voltage can be set to either 0, .006FS, or
.06FS. The analog amplifier gain can be set to LOW, MED, or HIGH.

4. All diagnostic testing is performed with the lamp turned off. The lamp can be turned on

or off by pressing the button marked LAMP. To determine if the lamp is on or off, inspect
the cuvette holder. If the lamp is on, light will be visible inside the cuvette holder.

5. With the voltage set to 0, the reading on the LCD is the background noise present in the

analog electronics, it will be different for each gain setting. The other two voltages (.006FS
and .06FS V) are typical of what the electronics would experience during normal opera-
tion.

6. To determine correct instrument operation, record all nine values and subtract the respec-

tive noise (0 reading) from the .006FS and the .06FS readings. Use the table below to
record the values.

7. The resulting six numbers will be used to determine if the instrument electronics and

digital processing are working correctly. The following table lists the expected values
and the tolerance of each value.

Gain

.006FS

.06FS

LOW

12 ± 5

125 ± 50

MED

125 ± 25

1,250 ± 250

HIGH

1,250 ± 200

12,500 ± 2,000

8. If the calculated values are within the ranges given above, the analog electronics and

digital processing is operating correctly. If the instrument fails this test, contact your local
Bio-Rad service representative.

LOW Gain

.006FS

.06FS

MED Gain

HIGH Gain