Delta OHM HD2109.1, Руководство по эксплуатации

Страница: 19 / 46

HD2109
- 19 -
V2.4
Polarographic probe and galvanic probe: differences
To help choosing between the use of a polarographic or galvanic probe, the following table summa-
rizes the main differences between the two probes.
Polarographic probe
DO9709SM
Galvanic probe
DO9709SG
Polarization time After connecting the probe to the in-
strument it is necessary to wait at
least 5 minutes before taking the
measurement. Polarization is not needed. After con-
necting the probe to the instrument it
is possible to take the measurement
immediately.
Flow rate Requires a lower flow rate (> 9 cm/s),
because it consumes less oxygen. Requires a higher flow rate (> 20 cm/s),
because it consumes more oxygen.
Electrodes life Longer, because the electrodes are
not consumed when the probe is dis-
connected from the instrument. Shorter, because the electrodes are
consumed even when the probe is
disconnected from the instrument (if
the electrolyte is not removed).
Maintenance Requires little maintenance. The electrolyte solution must be re-
placed more frequently.
Accuracy Higher accuracy (± 1% f.s.). Standard accuracy (± 2% f.s.).
Firmware update for DO9709SM and DO9709SG probes
The DO9709SM and DO9709SG probes are compatible with HD2109 instruments starting from
firmware version
2.08 . The instruments with previous firmware versions must be updated through
the DeltaLog 9 software. For the firmware updating procedure, see the instructions of the software.
Only for DO9709SM probes, after updating the firmware, you must perform the following ohmic ca-
libration:
1. With the instrument switched off, remove the connected SICRAM probe, if any.
2. Switch on the instrument.
3. When "SELF TEST" appears on display, press the REL button.
4. After the “self test”, the instrument displays the scrolling message "SET_ 0 DEG".
5. Connect the calibrator with value 1000 ohm to the instrument.
6. Wait a few moments for the detected value to be stable and press ENTER .
7. The instrument displays the scrolling message "SET_ 400 DEG".
8. Remove the calibrator with value 1000 ohm and connect the calibrator with value 2479 ohm
to the instrument.
9. Wait a few moments for the detected value to be stable and press ENTER .
10. The instrument displays the scrolling message "SET_ 0 DEG" again. Verify that calibration is
correct: the instrument must measure 0 °C when the calibrator with value 1000 ohm is con-
nected and 400 °C when the calibrator with value 2479 ohm is connected. If necessary, repeat
the calibration from step 5.
11. The calibration is complete, switch off the instrument.