wtw pH 3150i User manual

ba75679e01 01/2007
Handheld meter
pH 3150i
Operating manual
PH
6
4
2
99
6
°
C
TP
AR
CAL
M
O
pH measuring instrument

Accuracy when
going to press
The use of advanced technology and the high quality standard of our
instruments are the result of continuous development. This may result
in differences between this operating manual and your instrument. Al-
so, we cannot guarantee that there are absolutely no errors in this man-
ual. Therefore, we are sure you will understand that we cannot accept
any legal claims resulting from the data, figures or descriptions.
Warranty We guarantee the instrument described for 3 years from the date of
purchase.
The instrument warranty covers manufacturing faults that are discov-
ered within the warranty period. The warranty does not cover compo-
nents that are replaced during maintenance work, e.g. batteries.
The warranty claim extends to restoring the instrument to readiness for
use but not, however, to any further claim for damages. Improper han-
dling or unauthorized opening of the instrument invalidates any warran-
ty claim.
To ascertain the warranty liability, return the instrument and proof of
purchase together with the date of purchase freight paid or prepaid.
Copyright ©Weilheim 2007, WTW GmbH
Reproduction in whole - or even in part - is prohibited without the ex-
press written permission of WTW GmbH, Weilheim.
Printed in Germany.

pH 3150i List of contents
3
Contents
1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 SETs of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2 Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3 Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4 Jack field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1 Authorized use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . 10
3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.1 Switching on the measuring instrument . . . . . . . . . . . . . 13
4.2 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2.1 Measuring the pH value . . . . . . . . . . . . . . . . . . 15
4.2.2 Measuring the ORP voltage . . . . . . . . . . . . . . . 16
4.3 Calibrating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.3.1 AutoCal TEC . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.3.2 AutoCal DIN . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.4 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.5 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5 Maintenance, cleaning, disposal . . . . . . . . . . . . . . . . . 31
5.1 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.2 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
5.3 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6 What to do if... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
8 Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

List of contents pH 3150i
4

pH 3150i Overview
5
1Overview
The compact precision pH 3150i handheld meter enables you to carry
out pH measurements rapidly and reliably.
The pH 3150i handheld meter provides the maximum degree of oper-
ating comfort, reliability and measuring certainty for all applications.
The proven MultiCal®calibration procedure and the special AutoRead
function support you in your work with the pHhandheld meter.
Note
If you need further information or application notes, you can obtain the
following material from WTW:
zApplication reports
zPrimers
zSafety datasheets.
You will find information on available literature in the WTW catalog or
via the Internet.
1Keypad
2Display
3Jack field
PH
6
4
2
99
6
°
C
TP
AR
CAL
M
O
1
2
3

Overview pH 3150i
6
1.1 SETs of equipment
The measuring instrument is also available as part of individual SETs
of equipment.
You will find additional information on this and other accessories in the
WTW catalog or via the Internet.
Set (sample configuration):
1 Measuring instrument, pH 3150i
2 Stand
3–KCI solution for electrodes
–50 ml pH buffer solution, STP 4
–50 ml pH buffer solution, STP 7
–Beaker, 50 ml
4 pH electrode
4
3
2
1

pH 3150i Overview
7
1.2 Keypad
Key functions
RUN/ENTER
AR
CAL
M
Select the measuring mode <M>:
–pH value
–ORP voltage
Switch measuring instrument on/off
<ON/OFF>
Calibrate, select the calibration proce-
dure
<CAL>
Activate/deactivate the AutoRead
function
<AR>
Confirm entries,
start AutoRead
<RUN/ENTER>
M
CAL
AR
RUN/ENTER

Overview pH 3150i
8
1.3 Display
1.4 Jack field
Warning
Only connect electrodes to the measuring instrument that do not return
any unallowed voltages or currents (> SELV and > current circuit with
current limiting).
Almost all electrodes - in particular WTW electrodes - fulfill these con-
ditions.
1pH electrode
2Reference electrode
3Temperature probe
%
°F
S
ConCal
Auto Store
Time
Baud
Day.Month No.
Ident
Year
RCL
TempError
mg/L
% ppm
mol/L
ISE
8
8.
8
888
8
mV/pH
°C
UpH
LoBat
AutoCal DIN
CalError
ARng AR
AutoCal TEC
TP
1
Status display
Meas. value display
Function and
temperature display
Sensor symbol
Ref
12
3

pH 3150i Safety
9
2 Safety
This operating manual contains basic instructions that you must follow
during the commissioning, operation and maintenance of the measur-
ing instrument. Consequently, all responsible personnel must read this
operating manual carefully before working with the measuring system.
The operating manual must always be available within the vicinity of the
measuring system.
Target group The measuring instrument was developed for work in the field and in
the laboratory.
We assume that, as a result of their professional training and experi-
ence, the operators will know the necessary safety precautions to take
when handling chemicals.
Symbols
used
Warning
indicates instructions that must be followed to prevent damage to your
instrument.
Note
indicates notes that draw your attention to special features.
Note
indicates cross-references to other documents, e.g. application re-
ports, operating manuals of probes, etc.
2.1 Authorized use
The authorized use of the measuring instrument consists exclusively of
the pH and ORP measurement in the field and laboratory.
The technical specifications as given in chapter 7 TECHNICAL DATA must
be observed. Only the operation and running of the measuring instru-
ment according to the instructions given in this operating manual is au-
thorized.
Any other use is considered to be unauthorized.

Safety pH 3150i
10
2.2 General safety instructions
This instrument is built and inspected according to the relevant guide-
lines and norms for electronic measuring instruments (see chapter 7
TECHNICAL DATA).
It left the factory in a safe and secure technical condition.
Function and operating
safety
The smooth functioning and operational safety of the measuring instru-
ment can only be guaranteed if the generally applicable safety mea-
sures and the specific safety instructions in this operating manual are
followed during operation.
The smooth functioning and operational safety of the measuring instru-
ment can only be guaranteed under the environmental conditions that
are in specified in chapter 7 TECHNICAL DATA.
If the instrument was transported from a cold environment to a warm
environment, the formation of condensate can lead to the faulty func-
tioning of the instrument. In this event, wait until the temperature of the
instrument reaches room temperature before putting the instrument
back into operation.
Safe operation If safe operation is no longer possible, the instrument must be taken out
of service and secured against inadvertent operation!
Safe operation is no longer possible if the measuring instrument:
zhas been damaged in transport
zhas been stored under adverse conditions for a lengthy period of
time
zis visibly damaged
zno longer operates as described in this manual.
If you are in any doubt, please contact the supplier of the instrument.
Obligations of
the purchaser
The purchaser of the measuring instrument must ensure that the fol-
lowing laws and guidelines are observed when using dangerous sub-
stances:
zEEC directives for protective labor legislation
zNational protective labor legislation
zSafety regulations
zSafety datasheets of the chemical manufacturers.

pH 3150i Commissioning
11
3 Commissioning
Scope of delivery zHandheld meter, pH 3150i
zOperating manual and short operating manual
z4 batteries, 1.5 V Mignon type AA (in the instrument)
For details of scope of delivery of SETs, see chapter 1.1 SETSOF
EQUIPMENT and WTW catalog.

Commissioning pH 3150i
12

pH 3150i Operation
13
4 Operation
4.1 Switching on the measuring instrument
1Press the <ON/OFF> key.
The display test appears briefly on the display. Subsequently,
the slope and asymmetry that are used appear for approx. one
second one after the other. In addition, the calibration proce-
dure of the last calibration is shown (AutoCal TEC or
AutoCal DIN, or no display in the delivery state or after a reset).
The measuring instrument then switches to the measuring
mode that was last selected.
2 Connect the pH electrode to the measuring instrument.
The instrument is ready for operation.

Operation pH 3150i
14
4.2 Measuring
Preparatory activities Perform the following preparatory activities when you want to measure:
Note
Incorrect calibration of pH electrodes leads to incorrect measured val-
ues. Calibrate regularly before measuring.
Temperature sensor Basically, pH measurements should only be performed using a temper-
ature probe. The temperature probe is shown on the display by TP.
If you nevertheless use an electrode without a temperature probe, the
instrument operates with a reference temperature of 25 °C. Thus, the
sample and calibration solution must have their temperatures adjusted
to 25 °C in order to avoid larger measurement errors.
Note
The pH meter automatically recognizes the type of temperature probe
used. This enables electrodes to be connected with the NTC30 or
Pt1000.
1Connect the electrode to the measuring instrument.
2 Calibrate or check the measuring instrument with the elec-
trode.
3Select the measuring mode with <M>.

pH 3150i Operation
15
4.2.1 Measuring the pH value
Changing the
pH resolution
The measuring instrument shows the pH measured value with a reso-
lution of 0.01 or 0.001 (default setting is 0.01). To change over the res-
olution, press the <M> key while pressing the <RUN/ENTER> key.
AutoRead AR
(drift control)
The AutoRead function (drift control) checks the stability of the mea-
surement signal. The stability has a considerable impact on the repro-
ducibility of the measured values.
For identical measurement conditions, the following criteria apply:
Note
The current AutoRead measurement can be terminated at any time
(accepting the current value) by pressing <RUN/ENTER>.
1Perform the preparatory activities according to section 4.2.
2 Immerse the pH electrode into the test sample.
3Press the <M> key until pH appears on the status display. The
pH value appears on the display.
2
%
.
1
S
Time
Baud
Day.Month No.
Ident
Year
LoBat
CalError
TempError
ARng AR RCL
AutoCal DIN
AutoCal TEC ConCal
Auto Store
°F
mg/L
mV/pH
mol/L
% ppm
U
ISE
∆
8
4
2
99
6
°C
pH
TP
Reproducibility Response time
Better than 0.02 > 30 seconds
1Call up the pH measuring mode with <M>.
2 Activate the AutoRead function with <AR>.
The current measured value is frozen (hold function).
3Start AutoRead with <RUN/ENTER>.
The AR display indicator flashes until a stable signal is
reached.
4 If necessary, start the next AutoRead measurement with
<RUN/ENTER>.
5To terminate AutoRead: Press the <AR> key.

Operation pH 3150i
16
4.2.2 Measuring the ORP voltage
In conjunction with an ORP electrode, e.g. SenTix ORP, the measuring
instrument can measure the ORP voltage (U) of a solution.
Note
ORP electrodes are not calibrated. However, you can check ORP elec-
trodes using a test solution.
1Perform the preparatory activities according to section 4.2.
2 Immerse the ORP electrode in the test sample.
3Press the <M> key until U appears on the status display.
The ORP voltage (mV) of the sample appears on the display.
4 Wait for a stable measured value.
/pH
ConCal
Auto Store
LoBat
AutoCal DIN
CalError
ARng AR
AutoCal TEC
8
pH
1
%
°F
S
Time
Baud
Day.Month No.
Ident
Year
RCL
TempError
mg/L
% ppm
mol/L
ISE
3
1
2
2
0
mV
°C
U
TP
17

pH 3150i Operation
17
4.3 Calibrating
Why calibrate? pH electrodes age. This changes the asymmetry (zero point) and slope
of the pH electrode. As a result, an inexact measured value is dis-
played. Calibration determines the current values of the asymmetry
and slope of the electrode and stores them in the measuring instru-
ment.
Thus, you should calibrate at regular intervals.
Note
Always calibrate after replacing the pH electrode.
You can select between two calibration procedures:
AutoCal TEC is specially adapted to the WTW technical buffer solutions as a fully au-
tomatic two-point or three-point calibration. The buffer solutions are
automatically recognized by the measuring instrument. Depending on
the instrument setting (see section 4.4 CONFIGURATION), the instrument
displays the relevant buffer nominal value or the current electrode volt-
age in mV. The calibration can be terminated after the first buffer solu-
tion. This corresponds to a single-point calibration. To do this, the
instrument uses the standard slope (-59.2 mV/pH at 25 °C) and deter-
mines the asymmetry of the electrode.
AutoCal DIN is specially adapted to the permanently programmed buffer solutions in
accordance with DIN 19266 as a fully automatic two-point or three-
point calibration. The operating sequence of the AutoCal DIN calibra-
tion corresponds to that of the AutoCal TEC calibration. The calibration
can only be terminated after the first buffer solution (single point cali-
bration).
AutoRead When calibrating with AutoCal TEC and AutoCal DIN, the AutoRead
function is automatically activated.
The current AutoRead measurement can be terminated at any time
(accepting the current value) by pressing <RUN/ENTER>.
Displaying calibration
data
Each time the instrument is switched on, the calibration data are shown
on the display for a short time (see section 4.1 SWITCHING ON THE MEA-
SURING INSTRUMENT). In order to view the calibration data, switch the
measuring instrument off and switch it on again.

Operation pH 3150i
18
Calibration evaluation After the calibration, the measuring instrument automatically evaluates
the current status of the electrode. The asymmetry and slope are
evaluated separately. The worst evaluation appears on the display.
Display Asymmetry
[mV]
Slope
[mV/pH]
-15 ... +15 -60.5 ... -58
-20 ... +20 -58 ... -57
-25 ... +25 -61 ... -60.5
or
-57 ... -56
Clean the electrode according
to the electrode operating
manual
-30 ... +30 -62 ... -61
or
-56 ... -50
E3
Eliminate the error according to
chapter 6 WHAT TO DO IF...
< -30 or
> 30
... -62 or
... -50
1Connect the pH electrode to the measuring instrument.
2 Keep the buffer solutions ready.
3Adjust the temperature of the solution and measure the current
temperature if the measurement is made without the use of a
temperature sensor (the TP display indicator is missing from
the display).

pH 3150i Operation
19
4.3.1 AutoCal TEC
For this procedure, use any two or three WTW technical buffer solu-
tions in ascending or descending order
(pH values at 25 °C: 2.00 / 4.01 / 7.00 / 10.01).
Note
The calibration for pH 10.01 is optimized for the WTW technical buffer
solution TEP 10 Trace or TPL 10 Trace. Other buffer solutions can lead
to an erroneous calibration. The correct buffer solutions are given in the
WTW catalog or in the Internet.
Note
The buffer solutions are automatically recognized by the measuring in-
strument. Depending on the instrument setting (see section
4.4 CONFIGURATION), the instrument displays the relevant buffer nomi-
nal value or the current electrode voltage in mV.
1Press the <CAL> key repeatedly until the Ct1 display indicator
and the function display AutoCal TEC appears. The sensor
symbol displays the evaluation of the last calibration (or no
sensor symbol in the delivery state or after the measurement
parameter has been reset).
2Immerse the pH electrode in the first buffer solution.
3 Press the <RUN/ENTER> key. The AR display indicator flash-
es.
The electrode voltage (mV) or the buffer nominal value ap-
pears on the display. Example:
6
mV/pH
mol/L
8
Auto Store
RCL
LoBat
AutoCal DIN
CalError
ARng AR
ConCal
Time
Baud
Day.Month No.
Ident
Year
1
U
%
°F
S
TempError
mg/L
% ppm
ISE
8
4
2
1C t
°C
TP
pH
AutoCal TEC

Operation pH 3150i
20
Note
At this point, the AutoCal TEC calibration can be terminated with <M>.
This corresponds to a single-point calibration. To do this, the instru-
ment uses the standard slope (-59.2 mV/pH at 25 °C) and determines
the asymmetry of the electrode.
4When the measured value is stable, Ct2 appears.
5Thoroughly rinse the electrode with deionized water.
6 Immerse the pH electrode in the second buffer solution.
7Press the <RUN/ENTER> key.
The AR display indicator flashes.
The electrode voltage (mV) or the buffer nominal value ap-
pears on the display. Example:
AutoCal DIN AutoCal DIN
U
mV
U
mV/pH
mol/L
8
Auto Store
TempError
RCL
LoBat
CalError
ARng
ConCal
Time
Baud
Day.Month No.
Ident
Year
1
%
°F
S
mg/L
% ppm
ISE
8
4
2
°C
TP
mV/pH
mol/L
8
Auto Store
TempError
RCL
LoBat
CalError
ARng
ConCal
Time
Baud
Day.Month No.
Ident
Year
1
%
°F
S
mg/L
% ppm
ISE
8
4
2
0
1
°C
TP
80
4
pH
mV
AR
0
AR
pH
1 4
AutoCal TECAutoCal TEC
6
mV/pH
mol/L
8
Auto Store
RCL
LoBat
AutoCal DIN
CalError
ARng AR
ConCal
Time
Baud
Day.Month No.
Ident
Year
1
U
%
°F
S
TempError
mg/L
% ppm
ISE
8
4
2
2C t
°C
TP
pH
AutoCal TEC
U
1
mV
U
mV/pH
mol/L
8
Auto Store
TempError
RCL
LoBat
AutoCal DIN
CalError
ARng
ConCal
Time
Baud
Day.Month No.
Ident
Year
1
%
°F
S
mg/L
% ppm
ISE
6
8
4
2
°C
TP
mV/pH
mol/L
8
Auto Store
TempError
RCL
LoBat
AutoCal DIN
CalError
ARng
ConCal
Time
Baud
Day.Month No.
Ident
Year
1
%
°F
S
mg/L
% ppm
ISE
8
4
2
0
0
°C
TP
3
pH
mV
AutoCal TEC
AR
0
AR
AutoCal TEC
pH
37