vessel with a gas-tight closure can be used
for the digestion.
Computers, A/D cards, softwareWe must distinguish between the data
acquisition and data analysis roles of
the computer. For data acquisition, an
unsophisticated computer will suffice as
data logger. It should be able to support
one or more A/D cards, run the data collec-
tion software and present a real-time
graphic display of the voltage curves as
they are recorded. An IBM-compatible
machine, with a 386 or better CPU, running
Windows 3.1 is adequate. There are many
choices for the A/D card. The user should
ensure that the data collection software is
compatible with the card selected.216 P. Schofield
Fig. 10.2.Interior view of the Pell–Schofield box system containing a 20-place stirrer. The temperature
is regulated to ±0.5°C by switching the light bulb on and off. Two fans disperse the heat from this source.
The box is lined with 2.5 cm styrofoam. The temperature controller is on the top left and the sensor
power source (+10 V DC) on the top right. Only one sensor is shown connected. Overall dimensions
are 65 cm wide, 58 cm high, 72 cm deep. Directions for construction of the temperature controller and
wood-walled incubator have been published (Schofield, 1996).