A schematic diagram of the experimental setup is illustrated in
Fig. 1. The ohmic heater unit consisted of an open Pyrex glass T-tube
cylinder of 0.201 m length and 0.051 m inside diameter. Two titanium
electrodes were securely placed at the left and right ends of
the T-tube glass via a pair of spacers as in Fig. 2(a), and were connected
to an alternating current power supply (0e1000 V). The
temperature of the medium was continuously measured by using a
Teflon coated type-T thermocouple (Omega Eng. Inc., Stamford, CT)
and recorded by a data logger (21X, Campbell Scientific, Inc., Utah).
A tomato was placed between electrodes, and the residual space
filled with the medium. The thermocouple was also placed near the
tomato at the same position and depth for every run as seen in
Fig. 2(b). Data on voltage, current and time were recorded.