EUTECH INSTRUMENTS alpha TDS 200, Instruction Manual

Page: 17 / 40

17
7 TEMPERATURE CALIBRATION
IMPORTANT : When Calibration mode is entered, controller automatically goes into a
“HOLD” mode where the 4-20 mA output freezes and relays are de-activated (if it was in
an activated condition). Upon return to measurement mode, both 4-20mA output and
relay activities resume, depending on settings.
This controller features selectable Automatic Temperature Compensation (ATC) or
Manual Temperature Compensation (MTC).
ATC: ATC mode requires a Pt 100 temperature element. ATC automatically
compensates for temperature fluctuations. ATC temperature readings can be offset by
±10
o
C.
Important: If there is no temperature element wired to controller and ATC is selected on,
screen will flash in TDS mode, and an error message (OR) is displayed in temperature
mode.
MTC: MTC lets you select a specific value at which temperature will be compensated.
You can select a manual temperature value from 0 to 50
o
C. Factory default is 25.0
o
C.
See Setup program P4.0 for instructions on ATC or MTC selection.
To offset temperature:
1.
Press MODE to select
o
C mode. Display shows MTC or ATC, then temperature.
2. Key in password “011” as per procedure in Section 5.
3. The screen will flash current
o
C reading.
4. For ATC: Determine temperature of solution with an accurate meter (such as the
Temp 5). Press
▲ or ▼ keys to offset
o
C value on controller display to match value
of the solution you are measuring.
For MTC: Press
▲ or ▼ keys to offset
o
C value on controller display to match
desired value.
5. Press ENTER. The display flashes “DONE” for about 3 seconds and returns to
temperature measurement mode (Relays and 4-2- mA output resume activities as
per previous settings)