User Manual

32
• External and internal temperature control (ET)
ET 0: internal temperature control
ET 1: external temperature control
If the external temperature control (ET 1) is selected,
the following items EuT 2 (sampling time), Kp 2, Ti 2,
Td 2, Df t (maximum temperature difference between
internal and external temperature) and FAST could be
set. Otherwise they are not displayed in the menu list.
The sampling time EuT 2 (s) is the interval over which
the external control deviation and the respective con-
trol variable (dependent on Kp 2, Ti 2, Td 2, Df t and
FAST) is determined.
EuT 2 must be adjusted to match the response charac-
teristic (total of all time constants) of the external closed
loop controlled system, so that the control variable can
deliver a uniform and measurable change in the control
deviation. EuT 2 values that are too small or too large
can lead to instability of the controller.
Dynamics of the external PID temperature control (FAST)
FAST=0: accurate, without overshoot
FAST=1: fast, with overshoot
• Alarm and key tone (BEEP)
BEEP 0: no alarm and key tone
BEEP 1: alarm and key tone is activated
• Calibration and adjustment (CALI)
CALI 0: no calibration
CALI 2: 2-point calibration
CALI 3: 3-points calibration
Example: 2-point calibration:
Dip the temperature sensor of the reference measuring
instrument into the bath uid:
- If ET 0: into the internal bath (open the lid (16))
- If ET 1: at the same position as the external Pt100
temperature sensor (12).
Set the first point temperature (e.g. 80 °C). Confirm the
setting by pressing the right knob (C).
Left area of the display appears the set value (80 °C) and
the right area of the display appears the actual tempera-
ture value measured. The set LED (K) ashes briey.
The unit now starts and controls to the set value. When
the temperature has reached the set value and has be-
come constant, the “Set” LED (K) no longer ashes and
the following display appears.
The temperature measured by the unit appears on the
left hand side.
Input the calibration value from the reference mesuring
instrument (e.g. 80.2 °C) with the right knob (C).
Confirm the value by pressing the right knob (C).
Back to previous screen for input a new value by press-
ing the left knob (B).
Back OK
The first point calibration is finished now.
Calibration of the other points is performed in the same
way.
If ET 0: adjustment of the internal temperature mea-
surement.
If ET 1: adjustment of the external temperature mea-
surement.
Select 2-point calibration in the menu. Press the right
knob (C) to start the 2-point calibration.