Delta OHM HD2106.1, Руководство пользователя

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6) K CELL (Cell constant): sets the conductivity probe's cell constant nominal value. The
values 0.01, 0.1, 0.7, 1.0 and 10 cm
-1
(with tolerances from –30% to +50% of nominal
value) are admitted. The cell constant must be inserted before starting the probe calibration.
An ERR signal is generated if the cell constant's actual value exceeds the limits –30% or
+50% of nominal value. In this case it is necessary to check that the value set is correct, that
the calibration solutions are in good state, and then proceed with a new calibration.
The cell constant change entails resetting the calibration date: a new calibration updates the
calibration date.
7) LAST CAL m/d h/m (Last conductivity calibration) : the display shows the month and day
(m/d) in the main line, and the hour and minutes (h/m) in the secondary line of the previous
calibration of the conductivity probe. This menu item cannot be modified. The calibration year
is not displayed. The cell constant change, using the K CELL parameter, resets the date.
8) ALPH_T (Temperature coefficient
α
T
): the temperature coefficient
α
T
is the percentage
measurement of the conductivity variation according to temperature and is expressed in
%/°C (or %/°F). The admitted values vary from 0.00 to 4.00%/°C. Use the arrows (
and
) to set the desired coefficient
α
T
, and confirm with ENTER.
9) REF_TEMP (Reference temperature) : it indicates the temperature to which the displayed
conductivity value is standardized and can be equal to 20°C or 25°C. Using the arrows (
and ), set the desired value and confirm with ENTER.
10) TDS (Conversion factor
χ /TDS)
: it represents the ratio between the measured conductivity
value and the total quantity of dissolved solids in the solution, expressed in mg/l (ppm) or g/l
(ppt). This conversion factor depends on the nature of the salts present in the solution: in the
field of water quality treatment and control, where the main component is CaCO
3
(Calcium
Carbonate), a value of 0.5 is usually used. For agriculture water, for fertilizers preparation,
and in hydroponics, a factor of about 0.7 is used. Using the arrows (
and ), set the de-
sired value, selecting it in the 0.4…0.8 range, and confirm with ENTER.
11) RCD MODE (Record mode) : the instrument captures a conductivity and a temperature
value every second. If the RCD MODE parameter is set to " conductivity " (factory default),
the maximum (MAX) and minimum (MIN) values displayed using FUNC/ENTER refer to
conductivity: the indicated temperature is that measured at the maximum and minimum
conductivity and is not the maximum and minimum temperature.
If the RCD MODE parameter is set to "
tp " (=temperature), the maximum and minimum
values displayed using FUNC/ENTER refer to temperature: the indicated conductivity is
that measured at the maximum and minimum temperature and is not the maximum and
minimum conductivity.
Finally, if the RCD MODE parameter is set to "
Indep " (=independent), the maximum and
minimum values displayed using FUNC/ENTER are independent: the indicated conductivity
and temperature are the maximum and minimum measured values but are not necessarily re-
ferred to the same measurement moment.
12) Probe type : the message ">>>_PRBE_TYPE" is scrolled in the comment line. The main
line in the center of the display shows the type of temperature probe connected to the in-
strument. Conductivity/temperature combined probes with Pt100 or Pt1000 sensor, or tem-
perature only probes can be connected to the input:
•
4-wire Pt100 using the TP47 module
•
2-wire Pt1000 using the TP47 module
Upon being turned on, the instrument automatically detects the temperature probes: the
Probe Type menu item is configured by the instrument and cannot be modified by the user.