Hanna Instruments HI8931A User manual

Instruction Manual
HI8931A/B/C/D
HI8936A/B/C/D
HI8936AL/BL/CL/DL
HI943500A/B/C/D
Conductivity
Process Instrumentation
This Instrument is in Compliance with the CE Directives
WWW.HANNAINST.COM

32
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.
Note: Save all packing materials until you
are sure that the instrument functions
correctly. All defective items must be
returned in the original packing ma-
terials together with the supplied ac-
cessories.
The HI 8931 and HI 943500 are panel
mounted conductivity meters and control-
lers designed for simplicity of use in a wide
range of industrial process applications.
The instruments are designed with a stan-
dard DIN panel mount with membrane key-
pads on the front, a large LCD and with
auto-diagnostic functions.
Probes, power supply, contacts and record-
ers are connected on the rear panel through
screw terminals.
Using HI 8931 in conjunction with a 4-20 mA
output transmitter HI 8936 series (or HI 8936L
series, with LCD display) will assure you of
a strong, interference-free signal at distances
up to 300 meters (1000').
For in-line applications the probe should be
HI 7635 and for tanks HI 7638 with external
threads. These probes with built-in NTC sen-
sor, provide temperature compensated con-
ductivity measurements. The probe cable
length is 3 meters (10').
ISO 9000 Certified
Companysince1992
Dear Customer,
Thank you for choosing a Hanna Instruments
Product.
Please read this instruction manual care-
fully before using the instrument.
This manual will provide you with all the
necessary information for the correct use of
the instrument, as well as a precise idea of
its versatility in a wide range of applications.
These instruments are in compliance with
the directives EN 50081-1 and EN 50082-
1.
TABLE OF CONTENTS
Preliminary Examination........................... 3
General Description .................................. 3
Functional Description HI8931/HI943500. 5
Functional Description HI8936 ................. 9
Conductivity Probes................................ 12
Specifications HI8931 & HI943500......... 14
Specifications HI8936 ............................. 15
Connections ............................................ 16
Operational Guide................................... 24
Calibration Procedure of
HI8931 & HI8936 with HI7635................ 30
Calibration Procedure of
HI8931 & HI8936 with HI7638................ 34
Calibration Procedure of
HI943500 with HI7638 ............................ 38
Conductivity Versus
Temperature Chart ................................. 41
Diagnostic Tests ..................................... 42
Installation Examples.............................. 44
Probe Maintenance and Cleaning .......... 46
Accessories ............................................. 47
Warranty ................................................. 50
CE Declaration of Conformity ................ 51

54
FUNCTIONAL DESCRIPTION
HI 8931 & HI943500
KEYPAD
MEASURE To read the measurement values
and to enable the diagnostic tests
∆∆
∆∆
∆AL To display the set tolerance of
the alarm
SET To set the working point
TEST SLOPE Diagnostic function
TEST OFFSET Diagnostic function
When each key is pressed the LED is lighted
indicating to the user that the function is in
operation.
TRIMMERS
OFFSET For offset calibration
SLOPE For slope calibration
∆∆
∆∆
∆AL To set the alarm tolerance
COARSE Tocoarselyadjusttheworkingpoint
SET FINE Tofinely adjustthe workingpoint
LEDS
SET ON Toshowthatthedosageisactive
ALARM To show that the controller is in
alarm mode.
HI 943500 features a direct connection up
to 20 m (67'), without intermediate amplifi-
ers, to the conductivity probe HI 7638 with
7-pin DIN connector and automatic tempera-
ture compensation.
Four models with different measurement
ranges are available to suit individual appli-
cations:
HI8931A / HI943500A
HI8936A / HI8936AL
from 0.0 to 199.9 mS/cm
HI8931B / HI943500B
HI8936B / HI8936BL
from 0.00 to 19.99 mS/cm
HI8931C / HI943500C
HI8936C / HI8936CL
from 0 to 1999 µS/cm
HI8931D / HI943500D
HI8936D / HI8936DL
from 0.0 to 199.9 µS/cm
Other features include: recorder output in 0
to 20 mA or 4 to 20 mA configuration; LED
indicators (for HI8931 and HI943500) which
identify whether the controller is in opera-
tion mode or selection mode.
Each instrument is supplied with a plastic
front cover and two mounting brackets.
Power cables are excluded.
Transmitters and conductivity probes are
supplied separately.

76
THE REAR PANEL OF HI 943500A/B/C/D
Unplug the instrument from power
supply before the replacement of the
fuse.
1. Conductivity Probe Connector (7-pin DIN)
2. mA OUTPUT Terminals for connection
to a recorder
3. SET SELECT Terminal for reverse con-
trol operation
4. SET Terminals for connection to a dos-
ing pump
5. ALARM Terminals for connection to an
external alarm device
6. Power Supply
7. Fuse Holder.
Unplug the instrument from power
supply before the replacement of the
fuse.
THE REAR PANEL OF HI 8931A/B/C/D
1. ALARM CONT Terminals for connec-
tion to an external alarm device
2. SET CONT Terminals (Max. 2A, 220V)
for connection to a dosing pump
3.4. +20V and COMM Terminals for con-
nection to a conductivity transmitter
HI8936
5. SET SELECT Terminal for reverse con-
trol operation
6. 0-20/4-20mA Terminals for connection
to a recorder
7. Fuse Holder
8. Power Supply
9. IN/OUT TRANSMITTER Terminals for
connection to a conductivity transmitter.

98
FUNCTIONAL DESCRIPTION
HI 8936
1. Back Cover
2. Top Plastic Cover
3. LCD Display (for HI8936AL, HI8936BL,
HI8936CL, HI8936DL only)
4. Screws for fastening the top cover.
HI 8936A
HI8936B
HI8936C
HI8936D
HI 8936AL
HI8936BL
HI8936CL
HI8936DL
MECHANICAL DIMENSIONS
OF HI8931 AND HI943500
Front view of the panel-mounted unit
Thesedimensionsshowthecutoutsizeforthe
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" 144mm 5.67"
69mm
2.71"
72mm
2.83"

1110
MECHANICAL DIMENSIONS
OF HI8936A, HI8936B, HI8936C,
HI8936D
MECHANICAL DIMENSIONS
OF HI8936AL, HI8936BL, HI8936CL,
HI8936DL
110mm
4.33"
100mm
3.94"
HI 8614
165mm
6.50"
155mm
6.10"
4 x 4.3mm
4 x 0.17"
90mm
3.54"
110mm
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"
SIDE VIEW
HI 8936A HI8936B HI8936C HI8936D
HI 8936AL HI8936BL HI8936CL HI8936DL
1. Top Plastic Cover
2. Wire cable glands.

1312
HI7638 Tank Conductivity Probe
HI7638 conductivity probe combines the
proven 4-ring potentiometric method of mea-
suring 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 mainte-
nance.
The removable cover is made of Ultem®
which 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
CONDUCTIVITY PROBES
73mm
2.87"
52mm
2.04"
1" NPT
142mm
5.60"
HI 7635 In-line Conductivity Probe
HI7635 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 HI8936 conductivity transmitter.
The HI7635 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 polypropylene.
The maximum working pressure of this unit
is 5 BAR (72.5psi).
Do not use in systems where the tempera-
ture exceeds 80°C (176°F).
HI7635

1514
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
HI7635 for in-line applications or
HI7638 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 2% as
temperature coefficient (β)
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)
95% RH max
165 x 110 x 90 mm (LxWxH)
(6.5 x 4.3 x 3.5")
1 Kg (2.2 lb.)
Range
HI8936A&AL
HI8936B&BL
HI8936C& CL
HI8936D&DL
Accuracy
(@20°C/68°F)
Typical EMC
Deviation
ConductivityProbe
Calibration
Temperature
Compensation
Output
PowerSupply
HI8936A/B/C/D
HI8936AL/BL/CL/DL
Protection
Environment
Dimensions
Weight
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
HI8936 A or AL (not included)
HI8936 B or BL (not included)
HI8936 C or CL (not included)
HI8936 D or DL (not included)
------
HI7635 for in-line applications or
HI7638 for tank (not included)
Manual 2-point through offset
and slope trimmers
See transmitter HI8936
Automatic from 0 to 60°C with
2% as temperature coefficient(β)
4-digit LCD plus graphic
symbols
0 to 20 mA or 4 to 20 mA (isolated)
Isolated, 2A, Max. 240V,
resistive load, 1,000,000 strokes
Isolated, 2A, Max. 240V,
resistive load, 1,000,000 strokes
110/115V or 220/240V
(user selectable); 50/60 Hz
141 x 69 mm (5.6 x 2.7")
-10 to 50°C (14 to 122°F)
1 Kg (2.2 lb.)
DIN 43 700 144x72 mm
(5.7x2.8") in black anodized
aluminum. Front and back with
shockproof ABS plastic and a
transparent cover.
SPECIFICATIONS HI 8931 & HI 943500
Range
HI8931A - HI943500A
HI8931B - HI943500B
HI8931C - HI943500C
HI8931D - HI943500D
Accuracy
(@20°C/68°F)
Typical EMC
Deviation
4-20mA INPUT from
Transmitter
HI8931A
HI8931B
HI8931C
HI8931D
HI943500
Conductivity Probe
Calibration
Temperature
Compensation
HI8931
HI943500
Readout
Recorder Output
1 Set Point Relay
1 Alarm Relay
Power Supply
Panel Cutout
Environment
Weight
Enclosure

1716
• Set Select
These contacts permit
the activation of a Set
Contact relay when the
measured value is
lower (connected termi-
nals) or higher (open
terminals) than the
user's set value. See
also page 27.
• Alarm Contacts
During normal opera-
tion these terminals re-
main open.
If the measured con-
ductivity level is not
within the tolerance of
the set value, the alarm
contact is closed. These
contacts act only as a
switch.
See also page 28.
• +4-20 mA
These are the output
terminals for connec-
tion to a recorder or
other control equip-
ment.
The output current varies from 4 to 20 mA
and is proportional to the measured con-
ductivity value.
CONNECTIONS
REAR CONNECTIONS FOR HI8931
• Power Connection Terminals
(4-screw terminal strip)
for connection to a 3-
wire power cable ac-
cording to the indicated
voltage (115V or 230V).
• IN/OUT Transmitter
2 wires of the 4-core signal cable from the
conductivity transmitter
(HI8936) have to be
connected to these ter-
minals and the other 2
wires to the "+20V" and
"COMM" paying care-
ful attention to the po-
larity.
+20V supply is the regulated DC supply
required for the operation of the external
Conductivity Transmitter HI8936.
• Set Contacts
Dosing pumps or other
control equipment may
be connected to the
"SET CONT" (Max. 2A,
220V) terminals. These
contacts act only as a
"dry" switch allowing
electrical continuity, not
as a power supply.

1918
tivity controller (see
also page 24).
The 4-core cable has
to be connected to the
transmitter according to
the label instructions on
the 4-terminal strip.
The regulated D.C. supply required for the
proper operation of the transmitter is
"+20V", labeled "+20V" and "COM". The
current (mA) output terminals are labeled
"4-20 mA" and "COM".
The transmitter is protected against inver-
sion of supply voltage.
• HI8936 used in conjunction with an ex-
ternal power supply
Use 2 PVC insulated
2-core cables.
Connect a +20V DC
power supply directly to
the terminals labeled
"+20V" and "COM", paying careful atten-
tion to polarity (see also page 24) or if
necessary in series with the receiving de-
vice.
The regulated D.C. supply required for the
proper functioning of the circuit is marked
"+20V" and "COM", and the transmitter
current output is indicated "4-20 mA" and
"COM".
The transmitter is protected against inver-
sion of supply voltage.
The power unit should provide a voltage
of +20V ±25%.
Max. current required: 40 mA.
TERMINAL BOARD CONNECTIONS
FOR HI8936
•Remove the 4 screws and the top cover of
the HI8936 conductivity transmitter to ob-
tain access to the terminal board connections.
•
HI8936 used in conjunction with HI8931
controller
Use a PVC insulated 4-core cable to con-
nect the transmitter to the HI8931 conduc-

2120
REAR CONNECTIONS FOR HI 943500
• Power Connection Terminals
(4-screw terminal
strip) for connection to
a 3-wire power cable
according to the indi-
cated voltage (115V
or 230V).
• 7-pin 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 re-
corder or other control equipment. The
output current varies from 0 to 20 mA or
from 4 to 20 mA, depending on model,
and is propor-
tional to the mea-
sured conductivity
value.
• Set Select
These contacts
permit the activa-
tion of the Set
Contact relay
when the measured value is lower (closed
terminals) or higher (open terminals) than
the user's set value. See also page 27.
• Use of an amplifier
The maximum permissible distance be-
tween the power supply unit and the am-
plifier is 300 m (1000'). It is not necessary
to use a shielded cable.
•
Probe Connection
The conductivity probe
is supplied with a 3 m
(10'), 6 core cable. The
cable is to be con-
nected to the terminals
provided (see also
page 23 for proper con-
nection scheme of
HI7635 and HI7638).

2322
CONDUCTIVITY PROBE CONNECTIONS
The connections
for HI7635 are
color coded for
easy installation
and are as fol-
lows:
HI7635 cable HI8936 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
HI7638 are as fol-
lows:
HI7638 HI8936 transmitter
#1 probe pin 1
#2 probe pin 2
#3 probe pin 3
#4 probe pin 4
#5 NTC
#6 SENSOR
Note: NTC and SENSOR are equivalent and
are both labeled SENSOR on the
HI8936 conductivity transmitter.
• Set
Dosing pumps or other control equipment
may be connected to the "SET" (Max. 2A,
230V) terminals. These contacts act only
as a "dry" switch allowing electrical conti-
nuity, not as a power
supply.
• Alarm
Contacts
During normal opera-
tion these terminals
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 28.
connector
inside view

2524
mitter HI8936 to the terminals marked IN/
OUT TRANSMITTER paying careful atten-
tion to polarity. Connect the other 2 wires to
the +20V and COMM terminals paying care-
ful attention to polarity.
•The HI8936 transmitter
may be wall-mounted at
any convenient location
close to the measurement
site. To minimize thermal
drifts due to extreme tem-
perature fluctuations, par-
ticularly if the measure-
ment is conducted outdoors, it is recom-
mended that the transmitter is protected
in a casing.
•For the installation of the HI7635 conduc-
tivity probe, it is necessary to use rubber
seals between the probe and the pipe or
elbow joints. A pipe sealant is also recom-
mended to ensure a leak free joint. When
screwing on the joints, take care not to
overtighten as excessive pressures can
cause the probe to be damaged.
•The conductivity probe HI7635 is supplied
with a 3m (10') length of cable. The six
INITIAL PREPARATION & INSTALLATION:
Material needed:
• a 3-wire power cable (for connection of
HI8931/HI943500 to the mains)
•a PVC insulated 4-core cable ( as con-
nection cable between HI8931 and HI8936)
•rubber seals and a pipe sealant (for instal-
lation of HI7635)
FOR HI8931 AND HI8936 ONLY
•Remove the 4 screws
and the top of the
HI8936 Process Con-
ductivity transmitter.
•Connect the 3-wire
power cable to the 4-
screw terminal strip
according to the volt-
age level as indicated
and pay particular at-
tention to the correct
live, earth and neu-
tral terminal connec-
tions.
•Connect the 2 wires
connected to the
4-20mA and COM
terminals of the 4-
core signal cable from
the conductivity trans-
OPERATIONAL GUIDE

2726
OPERATING INFORMATION
The various parameters are set through the
front panel keys and trimmers.
When each key is pressed the correspond-
ing LED is lit, indicating that the function is
operational.
Make sure that the conductivity meter, trans-
mitter & probe are calibrated before using
the instrument for measurements (see page
30 & 34 for HI8931 & HI8936 and page 38
for HI943500).
SET POINT
To set the working point of the controller,
press the SET key. The display will indicate
the set value.
Use a small screw-
driver to adjust the
trimmers COARSE
and FINE until the
desired set value is
displayed.
Above set-point control operation
Leave the SET SELECT/
COMM. connectors open.
The set cont. relays will
close if the measured value SET
COMM.
SET
SELECT
core cable from the
probe is connected to the
HI8936 process conduc-
tivity transmitter as
shown. The connections are color coded
for an easy installation. See page 23 for
the proper connection scheme.
•It is recommended that the HI7635 is in-
stalled 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).
CAUTION: do not use in systems where
temperature exceeds 80°C
(176°F).
•The HI7638 process conductivity probe is
also supplied with a 3m (10')
length cable. The six core
cable from this probe is con-
nected to the HI 8936 pro-
cess conductivity transmitter
as shown.
The 7-pin DIN connector has to be re-
moved when this probe is used in con-
junction with HI8936 transmitter.
See page 23 for the proper connection
scheme.
FOR HI943500 ONLY
Ensure that the
HI7638 conductivity
probe is connected
to the meter se-
curely by aligning
the pins with the
socket, pushing the
plug in and tighten-
ing the threaded ring.

2928
When the alarm is active the
ALARM LED is lit.
The alarm contacts of HI 8931 remain open
duringnormaloperation. Ifthemeasured con-
ductivityvalueisnotwithinthetoleranceofthe
set value, the alarm contacts will be closed.
ThealarmcontactsofHI943500remainclosed
duringnormaloperation. Ifthemeasured con-
ductivity level is not within the tolerance of the
set value, the alarm contact will be open.
TAKING MEASUREMENTS WITH HI8931
AND HI943500
Aftersettingtheworkingpointandalarmvalue,
press the MEASURE key. The actual conduc-
tivity value of the test solution will be dis-
played.
TAKING MEASUREMENTS WITH
HI8936AL, HI8936BL, HI8936CL,
HI8936DL
Theconductivitytransmit-
terswithLCD willalways
displaythemeasurement
value when connected to
the HI8931 controllers or
a power supply.
is lower than the set-point
value and the SET ON LED
will be lit.
Below set-point control operation
Short the SET SELECT/
COMM. connectors with a
jumper wire.
The set cont. relay will close
if the measured value is
higher than the set-point
value and the SET ON LED
will be lit.
Note: The SET SELECT and COMM. relays
should be shorted or left open when
selecting the operation.
ALARM
Press the ∆AL key and the display will show
the set tolerance for the alarm.
Use a small screw-
driver to adjust the
trimmer ∆AL until the
desired tolerance is
displayed.
Example: If the set
value is 200 µS/cm
and a ∆Alarm of
50 µS/cm is set, an
alarm is activated every time the measured
value is higher than 250 µS/cm or lower
than 150 µS/cm.
SET
COMM.
SET
SELECT

3130
•Ensure that there is no solution inside the
HI7635 conductivity probe (dry probe).
•When the power is on, the ammeter should
read "4.0 mA". The HI8936L transmitter
with LCD should display "0".
•If not, adjust the OFF-
SET trimmer of the
HI8936 transmitter to
obtain "4 mA" or "0"
on the HI8936L.
•The HI8931 control-
ler should display "0"
value.
•If not adjust the OFF-
SET trimmer of
HI8931 to display a
zero reading.
•Switch the flow on
and allow the sample
solution to flow
through the HI7635
conductivity probe.
Collect a sample of
this solution in a bea-
ker.
•Measure the conduc-
tivity of the solution
with the HI8733 por-
table conductivity
meter with ATC. The
ins
rum ns
ON
OFF
HI 8733
199.9
mS
19.99
mS
1999
µS
199.9
µS
2.5
2
1.51
0.5
0
TEMPERATURE COEFFICIENT
µS
°C
CALIBRATION PROCEDURE OF
HI8931 & HI8936 WITH HI7635
Material Needed
•HI7635 conductivity probe
•HI8931 conductivity controller
• HI8936 conductivity transmitter
• A 20 mA f.s. ammeter (for transmitters
without LCD)
•Areference conductivity meter with auto-
matic temperature compensation accu-
rately calibrated (e.g. HI8733).
PROCEDURE
•Connect the HI7635 probe to the HI8936
transmitter (see page 23).
•Connect the HI8936 transmitter to the
HI8931 controller (see page 24).
•Connect the HI8931 controller to the mains
(see page 24).
Before proceeding with
the calibration, make sure
that the meter is in mea-
surement mode (MEA-
SURE LED will be lit) and not in set mode.
•Connect the ammeter to the HI8936 trans-
mitter to monitor the signal current (see
the following picture).
MEA
SURE

3332
HI8733 conductivity meter. E.g.
"123.4 mS".
•The calibration is now complete and the
instrument is ready for use. All subse-
quent measurements will now be compen-
sated to 25°C (77°F).
•If the instrument will not calibrate refer to
the Probe Maintenance and Cleaning sec-
tion (see page 46).
•If the HI8936 transmitter is not used in
conjunction with the HI8931 controller, con-
nect the transmitter to an external power
supply (see page 19). Connect the trans-
mitter to the HI7635 conductivity probe
(see page 23) and to an ammeter (see
page 19).
The calibration of the transmitters with LCD
(HI8936AL, HI8936BL, HI8936CL,
HI8936DL) does not require an ammeter.
Follow the above calibration procedure
performing the operations referred to the
HI8936 transmitter only.
value obtained will be used for the trans-
mitter and controller calibration.
•The reading will be converted to mA by
the following formula:
mA = K (measured value x 16 ) + 4
2000
K = conversion factor depending on the model
Model Conversion factor K
HI8936A & AL 10
HI8936B & BL 100
HI8936C & CL 1
HI8936D & DL 10
For example, using a HI8936A, if the mea-
sured value is 123.4 mS, then
output current = 10 x (123.4 x 16 )+4
2000
= 13.9 mA
Adjust the SLOPE
trimmer of the HI8936
transmitter to read
"13.9 mA" on the
ammeter or the read-
ing displayed by the
HI8733 conductivity meter on the
HI8936L display. E.g. "123.4 mS".
•Adjust the SLOPE trimmer of the HI8931
controller until the controller reading is the
same as the reading displayed by the

3534
•Leave the HI7638 conductivity
probe in air (dry probe).
•When the power is on, the ammeter should
read "4.0 mA" or the HI8936L transmit-
ter with LCD should display "0".
•If not adjust the OFF-
SET trimmer of the
HI8936 transmitter to
obtain "4 mA" or "0"
on the HI8936L.
•The HI8931 controller
should display "0"
value.
•If not adjust the OFF-
SET trimmer of
HI8931 to display a
zero reading.
CALIBRATION PROCEDURE OF
HI8931 & HI8936 WITH HI7638
Material Needed
•HI7638 conductivity probe
•HI8931 conductivity controller
• HI8936 conductivity transmitter
• An ammeter (for transmitters without LCD)
•Calibration solutions, according to the dif-
ferent models:
HI7034 80 mS/cm @25°C
for HI8931A, HI8936A & AL
HI7030 12.88 mS/cm @25°C
for HI8931B, HI8936B & BL
HI7031 1413 µS/cm @25°C
for HI8931C, HI8936C & CL
HI7033 84 µS/cm @25°C
for HI8931A, HI8936A & AL
PROCEDURE
•Connect the HI 7638 to the HI8936 trans-
mitter (see page 23).
•Connect the HI8936 transmitter to the
HI8931 controller (see page 24).
•Connect the HI8931 controller to the mains
(see page 24).
Before proceeding with
the calibration, make sure
that the meter is in mea-
surement mode (MEA-
SURE LED will be lit) and
not in set mode.
•Connect the ammeter to the HI8936 trans-
mitter to monitor the signal current (see
the following picture).
MEA
SURE

3736
•FOR HI8931
When the reading stabilizes, turn the
SLOPE trimmer on the front of the HI8931
until the LCD reading is the same as the
calibration solution at 25°C (77°F), i.e.
"80.0 mS" using HI7034 with HI8931A
"12.88 mS" using HI7030 with HI8931B
"1413 µS" using HI7031 with HI8931C
"84.0 µS" using HI7033 with HI8931D
•The calibration is now complete and the
instrument is ready for use. All subse-
quent measurements will now be compen-
sated to 25°C (77°F).
•If the instrument will not calibrate refer to
the Probe Maintenance and Cleaning sec-
tion (see page 46).
•If the HI8936 transmitter is not used in
conjunction with the HI8931 controller, con-
nect the transmitter to an external power
supply (see page 19). Connect the trans-
mitter to the HI7638 conductivity probe
(see page 23) and to an ammeter (see
page 19).
The calibration of the transmitters with LCD
(HI8936AL, HI8936BL, HI8936CL,
HI8936DL) does not require any amme-
ter.
Follow the above calibration procedure
performing the operations referred to the
HI8936 transmitter only.
•Pour enough conductivity
solution into a plastic bea-
ker to achieve at least
8 cm (3¼") of depth.
•Immerse the probe into the bea-
ker with the conductivity solu-
tion. The holes on the sleeve
must be completely submerged
in the solution.
•Tap the probe repeatedly on the bottom of
the beaker and stir it to ensure that no air
bubbles are trapped inside the sleeve.
•If the temperature of the probe is close to
that of the solution the display of HI8931
will stabilize quickly and provide a tem-
perature compensated conductivity mea-
surement. However, allow a few minutes
if there is a temperature difference of 5°C
(9°F) or more for the ATC circuitry to com-
pensate completely.
• For HI8936
Adjust the SLOPE trimmer of the HI8936
transmitter to read on the ammeter:
"10.4 mA" using HI7034 and HI8936A/AL
"14.304 mA" using HI7030 and HI8936B/BL
"15.304 mA" using HI7031 and HI8936C/CL
"10.72 mA" using HI7033 and HI8936D/DL
8 cm
(3¼")
HI 7030

3938
•Adjust the OFFSET trimmer if the LCD
does not show the zero reading.
•Pour enough conductivity
solution into a beaker to
achieve at least 8 cm
(3¼") of depth.
•Immerse the probe into the
beaker with the conductivity
solution. The holes on the
sleeve must be completely
submerged in the solution.
•Tap the probe repeatedly on the bottom of
the beaker and stir it to ensure that no air
bubbles are trapped inside the sleeve.
•If the temperature of the probe is close to
that of the solution the display will stabi-
lize quickly and provide you with a tem-
perature compensated conductivity mea-
surement.
However, allow a few minutes if there is a
temperature difference of 5°C (9°F) or more
for the ATC circuitry to compensate com-
pletely.
•When the reading stabilizes, turn the
SLOPE trimmer on the front of the
HI943500 until the LCD reading is the same
8 cm
(3¼")
HI 7030
CALIBRATION PROCEDURE OF
HI943500 WITH HI7638
Material Needed
•HI7638 conductivity probe
•HI943500 conductivity controller
•Calibration solutions, according to the dif-
ferent models:
HI7034 80mS/cm @25°C for HI943500A
HI7030 12.88mS/cm@25°C for HI943500B
HI7031 1413 µS/cm @25°C for HI943500C
HI7033 84 µS/cm @25°C for HI943500D
PROCEDURE:
•Ensure that the probe
is connected to the
meter securely by align-
ing 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 mode.