H72.0.11.6C-04
Operating Manual GMH 3451
page 15 of 18
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Error messages of automatic adjustment/calibration:
CAL Err.1 Cell correction too high
Determined cell correction must not exceed 1.2
CAL Err.2 Cell correction too small Determined cell correction must not fall below 0.8
CAL Err.3 Solution of wrong range
Wrong solution / far beyond tolerance
CAL Err.4 Wrong temperature
Beyond permitted temperature:
0.0 – 34.0 °C (or 0.0 – 27.0 °C at 111.8 mS/cm)
Alternative to automatic adjustment:
Manual calculation of cell correction
with a reference solution
Example KCl-solution c= 0.01 M: 1413
μ
S cm
-1
at 25°C
At other temperatures switch temperature compensation off (t.Cor = oFF) and use the referring conductivity!
Conductivity
displayed
= 1500
μ
S cm
-1
if selected cell correction is 1.000 cm
-1
(CELL Corr = 1.000)
Conductivity of solution at solution temperature 25 °C: Conductivity
real
= 1413
μ
S cm
-1
Cell correction c = conductivity
real
/ conductivity
displayed
[cm
-1
]
= 1413 / 1970 * cm
-1
= 0.942 cm
-1
(Enter CELL Corr of 0.942)
12 GLP
GLP (Good Laboratory Practice) includes regular check of devices and accessories. For pH measurements it
is highly important to ensure correct pH calibration. The device provides the following functions to help with
this.
12.1 Calibration interval (C.Int)
You can input the interval after which the device reminds you to recalibrate.
The interval times should be chosen according to the application and the stability of the electrode. “CAL”
flashes on the display as soon as the interval has expired.
12.2 Calibration storage (rEAd CAL)
The last 16 calibrations are stored with results and date and can be read out.
Display calibration data:
Historical calibration data can be comfortably read out via PC software GMHKonfig and GSOFT3050 or
displayed directly at the device:
Press for 2 seconds:
The display will show:
or
(configuration level)
Press several times until this is
displayed:
read cal. = “read calibration data”
Press shortly:
switch between:
- CELL = cell correction
- C.rEF = reference value, at which cell correction has been adjusted
- Display of date+time of data set
or
Change between the different calibration data sets
Quit calibration data set display
13 Alarm („AL.“)
There are 3 possible settings:
off (AL.oFF), on with buzzer (AL.on), on without buzzer (AL.no.So).
Alarm is given in the following cases (if alarm active, AL.on or AL.no.So):
-
Lower alarm boundary (AL. Lo) under-run
-
Upper alarm boundary (AL. Hi) over-rum
-
Sensor
error
-
Low
battery
(bAt)
-
Err.7: system error (always with buzzer!)
In case of an alarm (and when polling the interface) the ‘PRIO’-flag is set in the returned interface message.
4
Set
Menu
4
Set
Menu
3
CAL
2
max
5
min
