PRONOVA Stelzner EC 2000, Technical Instructions

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31
GB
Depending on the electrochemical reaction,
new glass soil-insertion electrodes will cau-
se a voltage difference of 58±2 mV when the
pH value changes by 1 unit. Usually, a glass
soil-insertion electrode will gradually dete-
riorate and the glass soil-insertion electrode
slope will decrease (due to pollution of the
sensitive membrane of the glass). This is why
it is necessary to re-calibrate it at certain in-
tervals.
Up to an electrode slope of 45 mV/pH unit, the
pH meter AGRAR 2000 may be calibrated wi-
thout complications. If the glass soil-insertion
electrode has deteriorated to that extent that
the glass soil-insertion electrode slope is <
45 mV/pH unit, the error message “E 1” will
appear and the measured value will flash.
Should the error “E 1” reappear after using a
new buffer solution, the glass soil-insertion
electrode has to be replaced.
Maintenance
pH glass insertion electrode will react more
slowly after the electrode has been stored
for long periods. The electrode can be reani-
mated by allowing it to soak overnight in a
buffer solution.
If there are any deposits on the three cera-
mic membranes, these diaphragms can be
carefully filed down with a nail file (file in
one direction only). Then let the pH electrode
soak in a buffer solution pH 4 or 7) of KCl so-
lution for 48 hours.
Refilling the KCl solution in pH glass insertion
electrode:
Push away the protective rubber collar and
refill with 3-mole/litre KCl electrolyte using a
pipette or syringe. The fill level should never
be allowed to sink more than 2 cm below the
electrode cap. Otherwise the reference elec-
trode can lose contact.
Note: The pH Agrar 2000 is equipped with a
battery voltage controller which checks the
battery status when the device is turned on.
Replace the battery if «LO BAT» is shown
on the display. The device may make false
measurements if the battery is not replaced.
TECHNICAL SPECIFICATIONS:
Range:
0 to 14
Degree of accuracy: 0.01
Precision:
±0.02
Display: LCD display
Operating temperature: +5 to +45 °C
Power supply: One nine-volt battery, size 6LR61
Service life: Approx. 100 h
Protection class: IP40
Dimensions and weight: 125 x 75 x 45 mm, 190 g
ART.-NO. ACCESSORIES
3010 Plastic pH electrode, for liquids
3011
Glass piercing pH electrode with
3 ceramic diaphragms
3012
Buffer solution pH 4, 100 ml bottle
3013
Buffer solution pH 7, 100 ml bottle
3014 Buffer solution pH 4, 1000 ml bottle
3015
Buffer solution pH 7, 1000 ml bottle
3026
Buffer tablets for calibration solution
5 tablets for pH 4
3027
Buffer tablets for calibration solution
5 tablets for pH 7
3016
Buffer tablets for calibrate solution
2 x 5 tablets for pH 4 and pH 7
0504
Calcium chloride (CaCl
2
) for soil analyses
(approx. 11.1 g for 10 l solution 0.01 mol/l)
1004
Spray bottle
3022
Refill solution with refill syringe for pH
electrodes 3 mol/l KCl, 100 ml bottle
3017
Dibble
3019
One nine-volt battery, GLRG1 size
pH AGRAR 2000