Hanna Instruments HI 8614 - Manual (Page 5)

9 8
pH CALIBRATION WITH AUTOMATIC
TEMPERATURE COMPENSATION
(HI 8614 & HI 8614L)
Initial preparation
• Connect the pH electrode
to the BNC socket.
• Connect the temperature
probe to the transmitter.
Pour small quantities of pH 7.01 and pH 4.01
solution into two clean beakers.
For accurate calibration use two beakers for
each buffer solution, the first one for rinsing
the electrode, the second one for calibration.
To get accurate readings, use pH 7.01 and
pH 4.01 if you are going to measure acid
samples or pH 7.01 and pH 10.01 for alkaline
measurements.
Note: with HI8614L the instruments display
can be used during calibration without
the need to connect the ammeter and
the reading is directly expressed in pH
units.
HI 7004 HI 7007
HI 7004
The wire between the transmitter and the
recorder/indicator/controller should be a PVC
insulated two wire with a wire diameter of at
least 0.7 mm. This wire is fed through one of
the smaller cable glands. The maximum dis-
tance between the power supply and the
amplifier is 300 m (1000'). It is not necessary
to use shielded cable. The transmitter is
protected against inversion of supply voltage.
Electrode connection: connect
the BNC of the cable to the BNC
socket on the transmitter.
For HI 8614 & HI 8614L only: for
automatic temperature com-
pensation, connect the 2 termi-
nals of the temperature probe
(HI 76608, optional) to "TEMP.
PROBE" terminals.
If automatic temperature compensation is not
required, short the "TEMP.
PROBE" terminals with a resis-
tance according to the external
temperature:
Temperature (°C) Resistance (Ohms)
0 1634
10 1774
20 1922
30 2078
40 2242
50 2412
60 2590
A 2 kohm resistor is factory mounted for 25°C
temperature compensation.
HI 7007
CALIBRATION
HI 7007
RINSE