Hanna Instruments HI 8931 User manual

Instruction Manual
HI 8931 • HI 8936 Series
HI943500 Series
Conductivity Process
Controllers and Transmitters
www.hannainst.com

32
Dear Customer,
Thank you for choosing a HANNA instruments®product.
Please read this instruction manual carefully before using the instru-
ment.
This manual will provide you with all the necessary information for
correct use of the instruments, as well as a precise idea of thier
versatility in a wide range of applications.
If you need additional technical information, do not hesitate to e-mail
us at [email protected]
These instruments are in compliance with the directives.
TABLE OF CONTENTS
Preliminary Examination ............................................................ 4
General Description .................................................................... 4
Functional Description HI 8931 & HI 943500 ............................ 6
Functional Description HI 8936 ................................................ 10
Conductivity Probes .................................................................. 13
Specifications HI 8931 & HI 943500 ....................................... 15
Specifications HI 8936 ............................................................. 16
Connections .............................................................................. 17
Operational Guide ................................................................... 25
Calibration Procedure of HI 8931 & HI 8936 with HI 7635 .... 31
Calibration Procedure of HI 8931 & HI 8936 with HI 7638 .... 35
Calibration Procedure of HI 943500 with HI 7638................... 39
Conductivity Versus Temperature Chart ..................................... 41
Diagnostic Tests ........................................................................ 42
Installation Examples ............................................................... 44
Probe Maintenance and Cleaning ............................................ 46
Accessories ................................................................................ 47
Warranty................................................................................. 49
CE Declaration of Conformity ..................................................... 50

54
Four models with different measurement ranges are available to suit
any application needs:
•HI8931A / HI 943500A / HI8936A / HI8936AL
from 0.0 to 199.9 mS/cm
•HI8931B / HI 943500B / HI8936B / HI 8936BL
from 0.00 to 19.99 mS/cm
•HI 8931C / HI 943500C / HI 8936C / HI8936CL
from 0 to 1999 μS/cm
•HI 8931D / HI 943500D / HI 8936D / HI8936DL
from 0.0 to 199.9 μS/cm
Other features include: recorder output in 0-20 mA or 4-20 mA
configuration; LED indicators (for HI 8931 and HI 943500) which
identify whether the controller is in operation mode or selection mode.
Each instrument of the HI 8931 and HI 943500 series, is supplied
with a plastic front cover and two mounting brackets. Power cables
are not included.
PRELIMINARY EXAMINATION
GENERAL DESCRIPTION
Remove the instrument from the packing material and examine it
carefully to make sure that no damage has occurred during shipping.
If there is any noticeable damage, notify your dealer.
Each model is supplied complete with:
• Mounting brackets (not for HI 8936 series)
• Transparent splsh-proof cover (not for HI 8936 series)
• Instruction manual
Note:Save all packing materials until you are sure that the
instrument functions correctly. All defective items must be
returned in the original packing materials together with
the supplied accessories.
The HI 8931 and HI 943500 are panel-mounted conductivity control-
lers designed for simplicity of use in a wide range of industrial process
applications.
The instruments are designed with a standard DIN panel mount with
membrane keypads and large LCD on the front, and provide a series
of auto-diagnostic functions.
Probes, power supply, contacts and recorders are connected on the
rear panel through screw terminals.
Using HI 8931 in conjunction with a 4-20 mA output transmitter
(HI 8936 or HI 8936L series) will assure you of a strong, interference-
free signal at distances up to 300 meters (1000').
For in-line applications use the HI 7635 probe, while for tanks the
HI 7638 with external threads is recommended. These probes are
provided with built-in NTC sensor for temperature compensated
conductivity measurements. The probe cable length is 3 meters (10').
HI 943500 features a direct connection up to 20 m (67'), without
intermediate amplifiers, to the conductivity probe HI 7638 with DIN
connector and automatic temperature compensation.

76
Unplug the instrument from power supply before
replacing the fuse.
REAR PANEL OF HI 8931 SERIES
1. POWER OUTPUT terminals (+20 V and COM) for connec-
tion to a conductivity transmitter (HI 8936)
2. mA INPUT from a conductivity transmitter
3. mA OUTPUT terminals for connection to a recorder
4. SET SELECT terminals for reverse control operation
5. SET terminals for connection to a dosing pump
6. ALARM terminals for connection to an external alarm device
7. Power supply terminals
8. Fuse holder
FUNCTIONAL DESCRIPTION
HI 8931 & HI 943500
KEYPAD
MEASURE To read measurements and enable diagnostic tests
ΔAL To display set tolerance of the alarm
SET To set working point
TESTSLOPE Diagnosticfunction
TESTOFFSET Diagnosticfunction
When a key is pressed, the corresponding LED lights up to indicate that
the function is active.
TRIMMERS
OFFSET Foroffset calibration
SLOPE For slope calibration
ΔAL To set the alarm tolerance
COARSE To coarsely adjust the set point
SET FINE To finely adjust the set point
LEDS
SETON To indicate that the dosage is active
ALARM To indicate an alarm condition

98
MECHANICAL DIMENSIONS
OF HI 8931 AND HI 943500
Front view of the panel-mounted unit
These dimensions show the cutout size for the installation.
Side view of the panel-mounted unit
Adjustable location brackets (supplied with the meter) allow the indicator
to slide into the cutout and will hold the unit securely in place. 190 mm
(7.50") is the minimum amount of room required to install the indicator
with the cables connected.
190mm MIN
7.50"
135mm
5.31"
0.25/4mm
0.01/0.160"
144mm
5.67"
ADJUSTABLE
LOCATION
BRACKET
141mm
5.55" 144m
m
5.67
"
69mm
2.71"
72mm
2.83"
REAR PANEL OF HI 943500 SERIES
1. DIN connector for conductivity probe
2. mA OUTPUT terminals for connection to a recorder
3. SET SELECT terminals for reverse control operation
4. SET terminals for connection to a dosing pump
5. ALARM terminals for connection to an external alarm device
6. Power supply terminals
7. Fuse holder
Unplug the instrument from power supply before
replacing the fuse.

1110
SIDE VIEW OF HI 8936 SERIES
1. Top cover
2. Cable glands for wiring
FUNCTIONAL DESCRIPTION HI 8936
1. Back cover
2. Top cover
3. Liquid Crystal Display
4. Screws for fastening the top cover
HI 8936A
HI 8936B
HI 8936C
HI 8936D
HI 8936AL
HI 8936BL
HI 8936CL
HI 8936DL

1312
CONDUCTIVITY PROBES
73mm
2.87"
52mm
2.04"
1" NP
T
142mm
5.60"
HI 7635 In-line Conductivity Probe
HI 7635 is a one piece, molded conductivity probe with pipe threads
(1" NPT) at both ends.
This allows the probe to attach to an in-line system, and to be used
in conjunction with the HI 8936 conductivity transmitter.
The HI 7635 uses a 4-ring potentiometric measuring method. This
method is highly accurate and requires very little maintenance.
The construction of the housing is rugged, fiber-reinforced polypropy-
lene.
The maximum working pressure of this unit is 5 bar (72.5 psi).
Do not use in systems where the temperature exceeds 80°C (176°F).
HI7635
MECHANICAL DIMENSIONS OF
HI 8936A, HI8936B, HI 8936C, HI8936D
MECHANICAL DIMENSIONS OF
HI 8936AL, HI8936BL, HI8936CL, HI8936DL
110m
m
4.33
"
100mm
3.94"
HI 8614
165mm
6.50"
155mm
6.10"
4 x 4.3mm
4 x 0.17"
90mm
3.54"
110m
m
4.33
"
100mm
3.94"
HI 8614L
165mm
6.50"
155mm
6.10"
90mm
3.54"
4 x 4.3mm
4 x 0.17"
126mm
5.00"
45mm
1.77"
24mm
0.94"
58mm
2.28"

1514
SPECIFICATIONS HI 8931 & HI 943500
0.0 to 199.9 mS/cm
0.00 to 19.99 mS/cm
0 to 1999 μS/cm
0.0 to 199.9 μS/cm
±2% of Full Scale
excluding probe error
±2.5% of Full Scale
±0.4 mA
HI 8936 A or AL (not included)
HI 8936 B or BL (not included)
HI 8936 C or CL (not included)
HI 8936 D or DL (not included)
------
HI 7635 for in-line applications or
HI 7638 for tank (not included)
Manual, 2 point, through
offset and slope trimmers
See transmitter HI 8936
Automatic, 0 to 60°C with ß=2%
4 to 20 mA (isolated)
Isolated, 2A, Max. 240V, resistive
load, 1,000,000 strokes
115 or 230 Vac ±10%
(user selectable); 50/60 Hz
-10 to 50°C (14 to 122°F); RH 95%
141 x 69 mm (5.6 x 2.7")
1 kg (2.2 lb.)
DIN 43 700, 144x72 mm (5.7x2.8"),
black anodized aluminum;
front and back with shockproof ABS
plastic, and transparent cover
Range
HI 8931A - HI 943500A
HI 8931B - HI 943500B
HI 8931C - HI 943500C
HI 8931D - HI 943500D
Accuracy
(@20°C/68°F)
Typical EMC
Deviation
4-20mA INPUT from
Transmitter
HI 8931A
HI 8931B
HI 8931C
HI 8931D
HI 943500
Conductivity Probe
Calibration
Temp. Compensation
HI 8931
HI 943500
Recorder Output
Set Point Relay and
Alarm Relay
Power Supply
Environment
Panel Cutout
Weight
Enclosure
HI7638 Tank Conductivity Probe
HI 7638 conductivity probe combines the proven 4-ring potentiometric
method of measuring conductivity with the platinum sensor and
stainless steel external thread.
This method incorporates a series of four platinum rings into the probe
shaft and is highly accurate requiring very little maintenance.
The removable plastic cover resists the harmful effect of most chemicals
and can be unscrewed for quick and simple maintenance.
This probe can withstand temperatures of up to 120°C (248°F) and
pressure of up to 5 bar (72.5 psi).
This probe is supplied complete with a 7-pin DIN connector.
HI 7638

1716
CONNECTIONS
REAR CONNECTIONS FOR HI8931
•Power Connection Terminals
4-screw-terminal-strip for connection
to a 3-wire power cable according to
the indicated voltage (115 or 230V).
•IN/OUT Transmitter
2 wires of the 4-core signal cable
from the conductivity transmitter
(HI8936) have to be connected to
the mA input terminals and the
other 2 wires to the "+20 V" and
"COM" while paying careful atten-
tion to the polarity.
+20 V supply is the regulated DC supply required for the
operation of the external conductivity transmitter HI 8936.
•Set Contacts
Dosing pumps or other control equip-
ment may be connected to the "SET"
(Max. 2A, 240 V) terminals. These
contacts act only as a "dry" switch
allowing electrical continuity, not as
a power supply.
SPECIFICATIONS HI 8936
0.0 to 199.9 mS/cm
0.00 to 19.99 mS/cm
0 to 1999 μS/cm
0.0 to 199.9 μS/cm
±2% of Full Scale
excluding probe error
±2% of Full Scale
±0.4 mA
HI 7635 for in-line applications or
HI 7638 for tank (not included)
Manual, 2 point, through
offset and slope trimmers
Fixed or automatic
from 0 to 50°C (32 to 122°F)
with ß=2%
4 to 20 mA not-isolated
max. 500 Ohm
12 to 30 Vdc
17 to 36 Vdc
IP 65
0 to 50°C (32 to 122°F);
RH max 95%
165 x 110 x 90 mm
(6.5 x 4.3 x 3.5")
1 kg (2.2 lb.)
Range
HI 8936 A/AL
HI 8936 B/BL
HI 8936 C/CL
HI 8936 D/DL
Accuracy
(@20°C/68°F)
Typical EMC
Deviation
Conductivity Probe
Calibration
Temperature
Compensation
Output
Power Supply
HI 8936 A/B/C/D
HI 8936 AL/BL/CL/DL
Protection
Environment
Dimensions
Weight

1918
TERMINAL BOARD CONNECTIONS FOR H8936
• Remove the 4 screws and the top cover of the HI 8936 conductivity
transmitter to obtain access to the terminal board connections.
•HI 8936 used in conjunction with HI 8931 controller
Use a PVC insulated 4-core cable to connect the transmitter to the
HI 8931 conductivity controller (see also page 25).
•Set Select
These contacts permit the activation
of a Set Contact relay when the
measured value is lower (connected
terminals) or higher (open termi-
nals) than the user's set value. See
also page 28.
•+4-20 mA
These are the output terminals for connection to a recorder or other
control equipment.
The output current varies from 4 to 20 mA and is proportional to
the measured conductivity value.
•Alarm Contacts
During normal operation these termi-
nals remain closed.
If the measured conductivity level is
not within the tolerance of the set
value, the alarm contact is open.
These contacts act only as a switch.
See also page 29.

2120
•Probe Connection
The conductivity probe is supplied
with a 3 m (10'), 6 core cable.
The cable is to be connected to the
terminals provided (see also page
24 for proper connection scheme of
HI 7635 and HI 7638).
The 4-core cable has to be con-
nected to the transmitter accord-
ing to the label instructions on the
4-terminal strip.
The regulated D.C. supply required for the proper operation of the
transmitter is "+20 V", labeled "+20 V" and "COM". The current
(mA) output terminals are labeled "4-20 mA" and "COM".
The transmitter is protected against inversion of supply voltage.
•HI 8936 used in conjunction with an external power supply
Use 2 PVC insulated 2-core cables.
Connect a +20 Vdc power supply
directly to the terminals labeled
"+20 V" and "COM", paying care-
ful attention to polarity (see also
page 24) or if necessary in series
with the receiving device.
The regulated DC supply required for the proper functioning of the
circuit is marked "+20 V" and "COM", and the transmitter current
output is indicated "4-20 mA" and "COM".
The transmitter is protected against inversion of supply voltage.
Max. current required: 40 mA.
•Use of an amplifier
The maximum permissible distance between the power supply unit
and the amplifier is 300 m (1000'). It is not necessary to use a
shielded cable.

2322
• Set
Dosing pumps or other control equipment may be connected to the
"SET" (Max. 2A, 240 V) terminals. These contacts act only as a
"dry" switch allowing electrical continuity, not as a power supply.
• Alarm Contacts
During normal operation these ter-
minals remain closed.
If the measured conductivity level
is not within the tolerance of the
set value, the alarm contact is
open. These contacts act only as a
switch. See also page 29.
REAR CONNECTIONS FOR HI943500
• Power Connection Terminals
4-screw-terminal-strip for connec-
tion to a 3-wire power cable ac-
cording to the indicated voltage
(115 or 230 V).
• DIN connector socket
For connection to the
HI 7638 conductivity
probe.
• + mA output -
The first and the second
terminals are the output
terminals for connection to
a recorder or other control
equipment. The output cur-
rent varies from 4 to 20
mA and is proportional to
the measured conductivity
value.
• Set Select
These contacts permit the
activation of the Set Contact relay when the measured value is
lower (connected terminals) or higher (open terminals) than the
user's set value. See also page 28.

2524
INITIAL PREPARATION & INSTALLATION
Material needed:
• a 3-wire power cable (to connec the HI 8931 or HI 943500 to
the mains)
• a PVC insulated 4-core cable (to connect the HI 8931 to HI8936)
• rubber seals and a pipe sealant (for installation of HI 7635)
FOR HI8931 AND HI8936 ONLY
• Remove the 4 screws and the
top of the HI 8936 conductivity
transmitter.
• Connect the 2 wires connected to
the "4-20 mA" and "COM" ter-
minals of the 4-core signal cable
from the HI 8936 to the termi-
nals marked "mA input" paying
careful attention to polarity.
Connect the other 2 wires to the
"+20 V" and "COM" terminals,
while paying attention to the
polarity.
• Connect the 3-wire power cable
to the 4-screw terminal strip ac-
cording to the voltage level as
indicated, and pay particular
attention to the correct live, earth
and neutral terminal connections.
OPERATIONAL GUIDE
CONDUCTIVITY PROBE CONNECTIONS
The connections for HI 7635
are color coded for easy in-
stallation and are as fol-
lows:
HI 7635 cable HI 8936 transmitter
Black or Grey NTC
Red or Pink SENSOR
Brown or Orange probe pin 1
Blue probe pin 2
White probe pin 3
Green or Yellow probe pin 4
The connections for HI 7638 are
as follows:
HI 7638 HI8936 transmitter
#1 probe pin 1
#2 probe pin 2
#3 probe pin 3
#4 probe pin 4
#5 NTC
#6 SENSOR
Note: NTC & SENSOR are equivalent, and are both labeled
"SENSOR" on the HI 8936 conductivity transmitter.
connector
inside view

2726
• It is recommended to install the HI 7635 vertically. This is to
ensure that trapped air bubbles or turbulent flows cause minimal
interference to the measurement system. The maximum working
pressure of this unit is 5 bar (72.5 psi).
WARNING: Do not use when temperature exceeds 80°C (176°F).
• The HI 7638 process conductivity probe is also
supplied with a 3 m (10') cable. The 6-core
cable of this probe is connected to the HI 8936
process conductivity transmitter as shown.
The DIN connector has to be removed when this probe is used in
conjunction with an HI8936 transmitter. See page 24 for the
proper connection scheme.
FOR HI943500 ONLY
Ensure that the HI 7638 con-
ductivity probe is connected
to the meter securely by align-
ing the pins with the socket,
pushing the plug in and
tightening the threaded ring.
• The HI 8936 transmitter may be
wall-mounted at any convenient loca-
tion close to the measurement site.
To minimize thermal drifts due to
extreme temperature fluctuations, par-
ticularly for outdoors measurements, it
is recommended to protect the trans-
mitter inside a casing.
• For the installation of the HI 7635 conductivity probe, use rubber
seals between the probe and the pipe or elbow joints. A pipe
sealant is also recommended to ensure a leak free joint. When
screwing the joints, take care not to overtighten as excessive
pressures can damage the probe.
• The HI 7635 conductivity probe is
supplied with a 3 m (10') cable. The
6-core cable of the probe is connected
to the HI 8936 transmitter as shown.
The connections are color coded for an
easy installation.
See page 24 for the proper connec-
tion scheme.

2928
Below Setpoint Control Operation
Short the "SET SELECT" and "COM" connec-
tors with a jumper wire. The set contact
relay will close if the measured value is
lower than the setpoint value, and the
"SET ON" LED will light up.
ALARM
Press the "ΔAL" key and the display will show the set tolerance for
the alarm.
Use a small screwdriver to
adjust the "ΔAL" trimmer un-
til the desired tolerance is dis-
played.
For example, if the set value
is 200 μS/cm and a ΔAlarm
of 50 μS/cm is set, an alarm
will be activated every time
the measured value is higher
than 250 μS/cm or lower
than 150 μS/cm.
When an alarm occurs, the "ALARM" LED
lights up.
COM
SET
SELECT
OPERATING INFORMATION
All parameters are set through the front panel keys and trimmers.
When any key is pressed, the corresponding LED lights up to indicate
that the function is active.
Make sure that the conductivity meter, transmitter and probe are
calibrated before taking measurements (see pages 31, 35 and 39 for
calibration procedures).
SET POINT
To set the working point of the controller, press the SET key. The
display will indicate the current set value.
Use a small screwdriver to
adjust the COARSE and FINE
trimmers until the desired
value is displayed.
Above Setpoint Control Operation
Leave the "SET SELECT" and "COM" connec-
tors open. The set contacts relay will close if
the measured value is higher than the
setpoint value, and the "SET ON" LED will
light up.
COM
SET
SELECT

3130
CALIBRATION PROCEDURE OF
HI 8931 & HI 8936 WITH HI 7635
Material needed:
•HI 7635 conductivity probe
•HI 8931 conductivity controller
•HI 8936 conductivity transmitter
• A 20 mA f.s. ammeter (for transmitters without LCD)
• A reference conductivity meter with automatic temperature com-
pensation accurately calibrated (e.g. HI 8733).
PROCEDURE
• Connect the HI 7635 probe to the H I8936 transmitter (see page
24 for details).
• Connect the HI 8936 transmitter to the H I8931 controller (see
page 25 for details).
• Connect the HI 8931 controller to the mains (see page 25 for
details).
Before proceeding with the calibration,
make sure that the meter is in measure-
ment mode ("MEASURE" LED is on) and
not in set mode.
• Connect the ammeter to the HI 8936 transmitter to monitor the
signal current (see below picture).
MEA
SURE
The alarm contacts of HI 8931 and HI 943500 remain closed during
normal operation. If the measured conductivity level is not within the
tolerance of the set value, the alarm contact will be open.
TAKING MEASUREMENTS WITH HI8931 AND HI943500
Aftersettingtheworkingpointandalarmvalue,pressthe"MEASURE"key.
The actual conductivity value of the test solution will be displayed.
TAKING MEASUREMENTS WITH HI8936AL, HI8936BL,
HI 8936CL, HI8936DL
The conductivity transmitters with LCD
will always display the measurement
value when connected to the HI8931
controllers or a power supply.

3332
• The reading will be converted to mA by the following formula:
mA = K (measured value x 16/2000) + 4
K = conversion factor depending on the model
Model Conversion factor K
HI 8936 A/AL 10
HI 8936 B/BL 100
HI 8936 C/CL 1
HI 8936 D/DL 10
For example, using an HI 8936A, if the measured value is 123.4
mS, then
output current = 10 x (123.4 x 16/2000)+4 = 13.9 mA
Adjust the HI 8936 SLOPE trim-
mer to read "13.9 mA" on the
ammeter, or the reading of the
HI 8733 (e.g. 123.4 mS) on
the HI 8936L display. .
• Adjust the HI 8931 SLOPE trimmer until the controller reading is
the same as the one displayed by the HI 8733 (e.g. 123.4 mS).
• Ensure that the HI 7635 conductivity probe is dry.
• When the power is on, the ammeter should read "4.0 mA".
The HI 8936 transmitter with LCD should display "0".
• If not, adjust the transmitter OFF-
SET trimmer to read "4 mA" or
"0" on the HI 8936 LCD.
• The HI 8931 controller should dis-
play "0" value.
• If not, adjust the HI 8931 OFF-
SET trimmer to display a zero
reading.
• Switch the flow on and allow the
sample solution to flow through
the HI 7635 conductivity probe.
Collect a sample of this solution in
a beaker.
• Measure the conductivity of the
solution with a reference conduc-
tivity meter with ATC (HI 8733).
The value obtained will be used
for the transmitter and controller
calibration.

3534
CALIBRATION PROCEDURE OF
HI 8931 & HI 8936 WITH HI 7638
Material needed:
•HI 7638 conductivity probe
•HI 8931 conductivity controller
•HI 8936 conductivity transmitter
• An ammeter (for transmitters without LCD)
• Calibration solutions, according to the different models:
HI 7034 80 mS/cm @25°C
for HI 8931A, HI 8936 A/AL
HI 7030 12.88 mS/cm @25°C
for HI 8931B, HI 8936 B/BL
HI 7031 1413 μS/cm @25°C
for HI 8931C, HI 8936 C/CL
HI 7033 84 μS/cm @25°C
for HI 8931D, HI 8936 D/DL
PROCEDURE
• Connect the HI 7638 to the HI 8936 transmitter (see page 24).
• Connect the HI 8936 transmitter to the HI 8931 controller (see
page 25).
• Connect the HI 8931 controller to the mains (see page 25).
Before proceeding with the calibration,
make sure that the meter is in measure-
ment mode ("MEASURE" LED is on) and
not in set mode.
• Connect the ammeter to the HI 8936 transmitter to monitor the
signal current (see below picture).
MEA
SURE
• The calibration is now complete and the instrument is ready for
use. All subsequent measurements will be compensated to 25°C
(77°F).
• If the instrument will not calibrate, refer to the "Probe Mainte-
nance and Cleaning" section on page 46.
• If the HI 8936 is not used in conjunction with the HI 8931
controller, connect the transmitter to an external power supply (see
page 20), to the HI 7635 conductivity probe (see page 24) and
to an ammeter (see page 20).
The calibration of the transmitters with LCD (HI 8936L series) does
not require an ammeter.
Follow the above calibration procedure performing the operations
referred to the HI 8936 transmitter only.

3736
• Pour at least 8 cm (3¼") of conductiv-
ity solution into a plastic beaker.
• Immerse the probe into the conductivity
solution. The holes on the sleeve must
be completely submerged in the solu-
tion.
• Tap the probe repeatedly on the bottom of the beaker and stir it
to ensure that no air bubbles remain trapped inside the sleeve.
• If the temperature of the probe is close to that of the solution, the
display of HI 8931 will stabilize quickly and provide a temperature
compensated conductivity measurement. Allow a few minutes if
there is a temperature difference of about 5°C (9°F) or more for the
ATC circuitry to compensate completely.
•For HI8936
Adjust the SLOPE trimmer of the HI 8936 transmitter to read on
the ammeter:
"10.4 mA" using HI 7034 and HI 8936 A/AL
"14.304 mA" using HI 7030 and HI 8936 B/BL
"15.304 mA" using HI 7031 and HI 8936 C/CL
"10.72 mA" using HI 7033 and HI 8936 D/DL
8 cm
(3¼")
HI 7030
• Leave the HI 7638 conductivity probe
in air (dry probe).
• When the power is on, the ammeter should read "4.0 mA" or the
HI 8936 transmitter with LCD should display "0".
• If not, adjust the HI 8936 OFF-
SET trimmer to obtain "4 mA" or
"0" on the HI 8936L.
• The HI 8931 controller should dis-
play "0".
• If not, adjust the HI 8931 OFF-
SET trimmer to display a zero
reading.

3938
CALIBRATION PROCEDURE OF
HI 943500 WITH HI 7638
Material needed
•HI 7638 conductivity probe
•HI 943500 conductivity controller
• Calibration solutions, according to the different models:
HI 7034 80mS/cm @25°C for HI 943500A
HI 7030 12.88mS/cm@25°C for HI 943500B
HI 7031 1413 μS/cm @25°C for HI 943500C
HI 7033 84 μS/cm @25°C for HI 943500D
PROCEDURE
• Ensure that the probe is con-
nected to the meter securely by
aligning the pins with the
socket, pushing the plug in and
tightening the threaded ring.
• Insert the probe into the sleeve.
• With the conductivity probe in
air, press the "MEASURE" key
to set the meter to measure-
ment mode.
•FOR HI8931
When the reading stabilizes, turn the SLOPE trimmer on the front
of the HI 8931 until the LCD reading is the same as the
calibration solution at 25°C (77°F), i.e.
"80.0 mS" using HI 7034 with HI 8931A
"12.88 mS" using HI 7030 with HI 8931B
"1413 μS" using HI 7031 with HI 8931C
"84.0 μS" using HI 7033 with HI 8931D
• The calibration is now complete and the instrument is ready for
use. All subsequent measurements will be compensated to 25°C
(77°F).
• If the instrument will not calibrate, refer to the "Probe Mainte-
nance and Cleaning" section on page 46.
• If the HI 8936 is not used in conjunction with the HI 8931
controller, connect the transmitter to an external power supply (see
page 20), to the HI 7638 conductivity probe (see page 24) and
to an ammeter (see page 20).
The calibration of the transmitters with LCD (HI 8936L series) does
not require any ammeter.
Follow the above calibration procedure performing the operations
referred to the HI 8936 transmitter only.