Thermo Fisher Scientific Alpha DO 2000 - Manual (Page 28)

Instruction manual
Alpha DO 2000
6.2 Electrode Offset Settings (OFS)
The electrode offset settings allow you to zero the transmitter without a
sensor. The use of a simulator is recommended. For real zero calibration,
use the calibration procedure as described in section 5. If no simulator is
used, a 22 k
Ω NTC must be connected to pins 24 and 25 of the terminal
connector on the backside of the unit (see section 3.2).
SETUP
HOLD
OFS
SETUP
HOLD
OFS
SETUP
HOLD
SETUP
HOLD
BAR
PRES
PRES
PRES
SETUP
HOLD
H9
SETUP
HOLD PSI
1.013
BAR
SETUP
HOLD
NO
OFS
OFS
SETUP
HOLD
YES
SETUP
HOLD 0.0
0.0
ppt
%
SAL
ENT ENT ENT ENT ENT
ENT
ENT
ENT This screen will not be
visible if DO Unit of
Measurement is set to %
(In Configuration settings)
1
3
2
2 5
6
6
6
7
SETUP
HOLD
ADJ
0.0 %
ENT
4
1. From the setup mode select the “OFS” screen and then press ENT key.
2. Selecting to modify offset value: By default, controller shows “NO OFS”.
Press ▲ or ▼ key to select “NO” or “YES” for offset adjustment.
− Select “NO OFS” to skip offset adjustment and move to the next step.
− Select “YES OFS” to perform offset adjustment.
Press ENT key to confirm your selection.
− If “YES OFS” was selected:
3. Selecting offset value: The display shows the offset from zero current of
the saturation or concentration. If this is within the range of -0.2 nA to 1.1 nA,
then the correction can be accepted. Press ENT key to confirm.
4. The display shows the offset. Press ENT key to confirm.
5. Setting salinity of the solution (SAL): This display only appears if the
measurement unit is set to “mg/l” or “ppm”. Press ▲ or ▼ key to set the
salinity of the solution. Press ENT key to confirm.
6. Setting the unit for pressure (PRES): Press the ▲ or ▼ key to set unit
(“BAR”, “mmHG”, “PSI”) of the barometric pressure. Press the ENT key to
confirm.
7. Setting barometric pressure: Press ▲ or ▼ key to set the barometric
pressure according to the selected unit in step 6. Press ENT key to confirm.
Continue with rest of the Setup procedures by pressing
▲ or ▼ key or return to
the Measurement mode by pressing ▲ and ▼ keys (escape) simultaneously.
20