Secondary Menu; Heater Power; Proportional Band - GE CTR 80 User Manual

Press "SET" to accept the new scan rate and continue.

S

9.4

Functions which are used less often are accessed within the secondary menu.

The secondary menu is accessed by pressing "SET" and "EXIT" simulta-

neously and then releasing. The first function in the secondary menu is the

heater power display. (See Figure 4 on page 36.)

9.5

The temperature controller controls the temperature of the bath by pulsing the

heater on and off. The total power being applied to the heater is determined by

the duty cycle or the ratio of heater on time to the pulse cycle time. By knowing

the amount of heating the user can tell if the calibrator is heating up to the

set-point, cooling down, or controlling at a constant temperature. Monitoring

the percent heater power will let the user know how stable the bath temperature

is.

The heater power display is accessed in the secondary menu. Press "SET" and

"EXIT" simultaneously and release. The heater power will be displayed as a

percentage of full power.

10.00C

S+E

SEC

12.0 P

To exit out of the secondary menu hold "EXIT". To continue on to the propor-

tional band setting function press "EXIT" momentarily or "SET".

9.6

In a proportional controller such as this the heater output power is proportional

to the well temperature over a limited range of temperatures around the

set-point. This range of temperature is called the proportional band. At the bot-

tom of the proportional band the heater output is 100%. At the top of the pro-

portional band the heater output is 0. Thus as the temperature rises the heater

power is reduced, which consequently tends to lower the temperature back

Accept scan rate

Bath temperature

Access heater power in secondary menu

Flashes

Heater power in percent

9 Controller Operation

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