Temperature Control
Oven status
50
In isothermal operation (
RATE
= 0 ), if
INIT TIME
is set equal to 0
(zero), the HP 5890 internally sets run time to the maximum, 650
minutes.
A
is included in key sequences defining parameters for a second ramp;
B
is included in key sequences defining parameters for a third ramp.
In isothermal operation, and in one•or two•ramptemperature programs,
rate for the next ramp must be set to 0 (zero) to prevent further
programming.
In oven temperature programming, once any one of the five temperature
programming functions (
INIT TEMP
,
INIT TIME
,
RATE
,
FINAL TEMP
, and
FINAL TIME
) is displayed, pressing
ENTER
, without entering a new
setpoint value, rolls the display successively through the entire group,
(including A and B displays for second and third ramps).
This is an efficient way in which to review and, if necessary, change oven
temperature program setpoints.
Oven status
During a temperature•programmedrun, the LED OVEN display provides
indication of oven status at any given time:
Isothermal Run: Assuming
INIT TIME
is assigned a value greater
than 0, and that
RATE
=0,only the INITIAL TIME LED is lit. It
remains lit throughout the run.
Single•Ramp Temperature Program: The three LEDs, INITIAL
TIME, RATE, and FINAL TIME, successively light to indicate position
in the temperature program.
Multiple•Ramp Temperature Program: The three LEDs, INITIAL
TIME, RATE, and FINAL TIME, successively light to indicate position
in the first temperature program ramp.
Then RATE and FINAL TIME LEDs light alternately as the program
proceeds through the second (and third) ramp(s).
