Cosa 9610, Инструкция по установке, эксплуатации и обслуживанию

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INSTALLATION, OPERATION AND MAINTENANCE MANUAL – COSA 9610™
Page 39 of 48
3.4. T
EMPERATURE
C
ONTROLLED
O
VEN
3.4.1. Furnace temperature control unit
The zirconia cell must operate at a temperature above 600ºC. For optimal performance, a
set-point temperature of 812ºC was chosen. The oven that serves as the heating device
for the zirconia cell is made of a metal wire-wound heating element. To minimize energy
consumption, the heating element is encapsulated by glass-fibre insulating material. The
driving voltage for the heater is 120VAC. The power is controlled by computer.
The temperature controller utilizes a PID algorithm to drive a solid-state relay, which in its
turn controls the on/off ratio of the voltage to the heater element. To generate alarms,
and to enable the system to compensate for temperature changes.
The oven temperature is controlled by software included in the operating system of the
analyzer. All settings are factory programmed but may need to be fine tuned depending
on local conditions. However, for servicing purposes it can be useful to change the
temperature of the oven. The temperature of the oven is displayed on the right hand side
of the display screen.
By accessing the Temperature menu is the measurement screen, one can increase the
temperature set-point. The oven needs about half an hour to heat up to 812ºC. Normal
on/off-ratio is about 85%. This allows for a stable temperature control and long lifetime of
the oven (typically 2 – 8 years).