Knick Stratos 2201 pH, Stratos 2211 pH, Stratos 2201 X pH, Stratos 2211 X pH Instruction Manual

Instruction Manual

Stratos 2201 (X) pH
Stratos 2211 (X) pH with
HARTr Communication

Software Version: 3.x

TA-194.100-KNE03 150101

Elektronische Meßgeräte
GmbH & Co.
Beuckestr. 22, D–14163 Berlin
Postfach 37 04 15, D–14134 Berlin
Phone: [phone]
Fax: [phone]
Internet: http://www.knick.de
E-mail: [e-mail]

Warranty

Defects occurring within 3 years from delivery date shall
be remedied free of charge at our plant (carriage and
insurance paid by sender).
Accessories: 1 year

Note

Changes 3

Changes for software release 3

T emperature probe adjustment

The Stratos can be adjusted to a connected temperature probe.
This is particularly useful for Pt 100 temperature probes.
(See Pg. 32)

This function should only be used by experts. Incorrectly set parameters may go unnoticed,
but change the measuring properties.

Changes 4

Warning

Warning

Information 5

Safety Precautions

Be sure to read and observe the following requirements!

Never use the Stratos 2201/2211 pH for measurement in areas that are subject to an explo­sion hazard during operation.
Be sure that the supply voltage does not exceed 30 Vdc.

Stratos 2201/221 1 X pH is approved for operation in hazardous locations.
Before connecting the Transmitter to a power supply unit, make sure that this is an associ­ated apparatus.

Whenever it is likely that the protection has been impaired, the instrument shall be made inoperative and
secured against unintended operation.
The protection is likely to be impaired if, for example:

❏ the instrument shows visible damage
❏ the instrument fails to perform the intended measurements
❏ after prolonged storage at temperatures above 70 °C
❏ after severe transport stresses

Before recommissioning the instrument, a professional routine test in accordance with EN 61010-1 must be
performed. This test should be carried out at our factory.

The instrument shall not be used in a manner not specified by this manual.

cal

Note

Warning

conf

cal

Information 6

Information on this Instruction Manual

ITALICS are used for texts which appear in the Stratos 2201/2211 (X) pH display.

Bold print is used to represent keys, e.g. cal.

Keys for which the functions are explained are frequently shown in the
left-hand column.

Notes provide important information that should be strictly followed when using the unit.

Warning means that the instructions given must always be followed for your own safety.
Failure to follow these instructions may result in injuries.

Mode Codes

After pressing conf or cal you can enter one of the following codes to access the desig-
nated mode:

conf, 0000: Error info
conf, 1200: Configuration
conf, 5555: Current source

cal, 0000: Cal info
cal, 1015: Temperature probe adjustment
cal, 1100: Calibration
cal, 2222: T est mode (electrode potential display)

Contents 7

Contents

Safety Precautions 5. . . . . . . . . . . . . . . . . . . . . .

Information on this Instruction Manual 6. . .

Mode Codes 6. . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 Assembly 8. . . . . . . . . . . . . . . . . . . . . . . . . . .

Package Contents and Unpacking 8. . . .

Assembly 8. . . . . . . . . . . . . . . . . . . . . . . . . .

2 Installation, Connection

and Commissioning 12. . . . . . . . . . . . . . . . .

Proper Use 12. . . . . . . . . . . . . . . . . . . . . . . .

Overview of the Stratos 12. . . . . . . . . . . . . .

T erminal Assignment 13. . . . . . . . . . . . . . . .

Installation and Commissioning 13. . . . . . .

Wiring Diagrams (pH) 14. . . . . . . . . . . . . . .

Wiring Diagrams (ORP) 19. . . . . . . . . . . . .

3 Operation 20. . . . . . . . . . . . . . . . . . . . . . . . . . .

User Interface 20. . . . . . . . . . . . . . . . . . . . . .

Display 21. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Keypad 21. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Safety Functions 22. . . . . . . . . . . . . . . . . . . .

Outputs 23. . . . . . . . . . . . . . . . . . . . . . . . . . .

Configuration 24. . . . . . . . . . . . . . . . . . . . . . .

Calibration 26. . . . . . . . . . . . . . . . . . . . . . . . .

Measurement 33. . . . . . . . . . . . . . . . . . . . . .

4 Diagnostics, Maintenance and Cleaning 34

Sensoface



, Sensocheck



34. . . . . . . . . .

Error Messages 35. . . . . . . . . . . . . . . . . . . .

Calibration Error Messages 37. . . . . . . . . .

Diagnostics Functions 38. . . . . . . . . . . . . . .

Maintenance and Cleaning 39. . . . . . . . . . .

5 Annex 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Product Line 40. . . . . . . . . . . . . . . . . . . . . . .

Specifications 41. . . . . . . . . . . . . . . . . . . . . .

Certificate of Conformity 44. . . . . . . . . . . . .

Buffer Charts 47. . . . . . . . . . . . . . . . . . . . . . .

Technical Terms 49. . . . . . . . . . . . . . . . . . . . . . . . .

Index 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Assembly 8

1 Assembly

Package Contents and Unpacking

Unpack the instrument carefully and check the ship­ment for transport damage and completeness.
The package contains:

–Front unit of Stratos 2201/2211 (X) pH
–Lower case
–Short instruction sheet
–This instruction manual

–Bag containing:

➀ 2 sealing plugs ➆ 1 hinge pin
➁ 5 hexagon nuts ➇ 3 cable ties
➂ 3 Pg cable glands ➈ 3 filler plugs
➃ 1 rubber reducer ➉ 3 gaskets
➄ 1 Pg plug

11 1 washer

➅ 4 enclosure screws

12

1 jumper

Assembly

Fig. 1 Assembling the case

➀

(For sealing in case

of wall mounting)

➁

➂

➃

➄

➅

➆

(Can be inserted
from either side)

➇

➈

➉

11

For conduit mounting:
Place washer
between enclosure
and nut.

11

12

Assembly 9

80 [3.15]

32 [1.26]

72 [2.83]

6.2 [0.24]

approx. 14

84 [3.31]

42 [1.65]

Pg 13.5 (3 pcs.)

144 [5.67]

144 [5.67]

21

43 [1.69]

105 [4.13]

27

(not included in supply)

Control panel 1 – 22 mm

max. 25

78 [3.07]

27

Control panel cutout
138 x 138 mm (DIN 43700)

Panel-mount kit
consisting of:

4 screws
4 span pieces
4 threaded sleeves
1 seal

➀
➁
➂
➃

➃

➀

➁

➂

Holes for
post mounting

Holes for
wall mounting

(4 x)

(2 x)

For Pg 13.5 threaded cable glands
(use only plastic glands)

[0.55]

[1.06]

[0.83]

[0.98]

[1.06]

[5.43 x 5.43]

[0.04 – 0.87]

Note: All dimensions

in mm [inches]

Fig. 2 Dimension drawing for Stratos, mounting diagram and ZU 0275 panel-mount kit

Assembly 10

horizontal post/

40–60 mm dia.

➀

➁

➂

ZU 0276 protective hood
(if required)

For vertical or
pipe mounting

Pipe-mount kit
consisting of:

4 self-tapping screws
1 post mounting plate
2 hose clamps with

➀
➁
➂

worm gear drive
to DIN 3017

[1.57–2.36]

Fig. 3 ZU 0274 pipe-mount kit

165 [6.5]

173 [6.81]

132 [5.2]

Fig. 4 ZU 0276 protective hood for wall and pipe mounting

Assembly 11

280 [11.03]

7 [0.28]

➀ Recommended stripping lengths for

multi-core cables

➁ Recommended stripping length for

coaxial cable

➂ Pulling out the terminals using a

screwdriver (also see

➆)

➃

Cable laying in the Stratos

➄ Connecting lines for loop current
➅ Cover for electrode and temperature

probe terminals

➆ Areas for placing the screwdriver to

pull out the terminals

➇ Connection of handheld terminal

➀

➁

➃

➄

Be sure not to

notch the cable
cores when stripping
the insulation!

Dimensions in mm [inches].

➄

➅

➆

➇

Coaxial cable

13 mm [0.5]

7 mm [0.28]

➂

Fig. 5 Installation information Stratos 2201/2211 (X) pH

Warning

Warning

Capabilities, Connection 12

2 Installation, Connection and Commissioning

Proper Use

Stratos 2201/2211 (X) pH is used for pH and temper­ature measurement in industry, the environment,
food processing and waste-water field. It can be
either field-mounted or fixed into a control panel.

Never

use the Stratos
2201/221 1 pH for measurement in
areas that are subject to an explo­sion hazard during operation.

Stratos 2201/2211 X pH is ap­proved for operation in hazardous
locations.

Overview of the Stratos

pH / mV
Sensocheck



Temperature
Pt 100/1000/
NTC 30 kW

Stratos 2201/2211 (X) pH

mA

➀

➁

➂

➃

Fig. 6 System functions of Stratos 2201/2211 (X) pH

➀ Inputs for glass and reference electrode
➁ Input for temperature probe
➂ Current loop 4 – 20 mA,

transports power to and output signal from the
Stratos,

with Stratos 2211 (X) pH also for HARTr commu­nication

④ Equipotential bonding (only with Stratos

2201/2211 X pH)

Warning

Warning

Warning

Warning

Warning

Warning

Capabilities, Connection 13

T erminal Assignment

+ 11 10

4 to 20 mA

+

–

glass el.

9 8 7 6 5 4 2 1

í

output input

shield

–

aux el.

n.c.

HART



observe grounding conditions

reference el.

Fig. 7 Terminal assignment of Stratos 2201/2211 (X) pH

Installation and Commissioning

Installation and commissioning of
the Stratos may only be carried out
in accordance with this instruction
manual and per applicable local
and national codes. Be sure to ob­serve the technical specifications
and input ratings.

Before connecting the Stratos
2201/221 1 pH to a power supply
unit, make sure that this is not ca­pable of outputting more than
30 Vdc.

Do not use alternating current or
mains power supply!

Stratos 2201/2211 X pH may only
be connected to an explosion-proof
power supply unit (for input ratings
refer to annex of Certificate of Con­formity).

When commissioning, a complete
configuration must be carried out.

For easier installation, the terminal strips are of a
plug-in design. The terminals are suitable for single

wires and flexible leads up to 2.5 mm

2

(AWG 14)

(see Pg. 11).
See Pg. 14 and following for connection examples.

Do not use cable clamp (shield) for
reference electrode connection
when auxiliary electrode (solution
ground) is in use.

Capabilities, Connection 14

Wiring Diagrams (pH)

reference el.

glass el. +

í

í

shield

aux. el.

8 7 4

2 1

54 21

5

Temperature
probe

Combination
electrode

Fit jumper between
terminals 4 + 5.

Fig. 8a pH measurement with combination electrode and temperature probe,

Sensocheck



limited to the glass electrode only

54 21

í

Temperature
probe

Combination
electrode

shield

Fit jumper between
terminals 4 + 5.

reference el.

glass el. +

í

aux. el.

8 7 4

2 1

5

Fig. 8b pH measurement with combination electrode and temperature probe,

Sensocheck



limited to the glass electrode only

Capabilities, Connection 15

Combination
electrode

shield

54 21

Specify temperature!

Fit jumper between
terminals 4 + 5.

reference el.

glass el. +

í

aux. el.

8 7 4

2 1

5

Fig. 9 pH measurement with combination electrode without temperature probe,

Sensocheck



limited to the glass electrode only

Capabilities, Connection 16

54 21

í

shield

reference el.

glass el. +

í

aux. el.

8 5 4

2 1

7

Temperature
probe

Glass
electrode

Reference
electrode

Fit jumper between
terminals 4 + 5.

Fig. 10 pH measurement with separate glass and reference electrode and temperature probe,

Sensocheck



limited to the glass electrode only

54 21

shield

reference el.

glass el. +

í

aux. el.

8 5 4

2 1

7

Glass
electrode

Reference
electrode

Specify
temperature!

Fit jumper between
terminals 4 + 5.

Fig. 11 pH measurement with separate glass and reference electrode without temperature probe,

Sensocheck



limited to the glass electrode only

Capabilities, Connection 17

reference el.

glass el. +

í

í

shield

aux. el.

8 5 4

2 1

54 21

7

Temperature
probe

Combination
electrode

Aux.
electrode

Insulate!

Fig. 12 pH measurement with combination and aux. electrode and temperature probe,

Sensocheck



for glass and reference electrode

reference el.

glass el. +

í

shield

aux. el.

8 5 4

2 1

54 21

7

Combination
electrode

Aux.
electrode

Specify
temperature!

Insulate!

Fig. 13 pH measurement with combination and aux. electrode without temperature probe,

Sensocheck



for glass and reference electrode

Capabilities, Connection 18

54 21

í

shield

reference el.

glass el. +

í

aux. el.

8 5 4

2 1

7

Temperature
probe

Glass
electrode

Reference
electrode

Aux.
electrode

Fig. 14 pH measurement with separate glass, reference and aux. electrode and temperature probe,

Sensocheck



for glass and reference electrode

54 21

shield

reference el.

glass el. +

í

aux. el.

8 5 4

2 1

7

Glass
electrode

Reference
electrode

Aux.
electrode

Specify
temperature!

Fig. 15 pH measurement with separate glass, reference and aux. electrode without temperature probe,

Sensocheck



for glass and reference electrode

Capabilities, Connection 19

Wiring Diagrams (ORP)

54 21

í

shield

reference el.

glass el. +

í

aux. el.

8 7 4

2 1

5

Insulate!

Temperature
probe

combination
ORP electrode

Fig. 16 ORP measurement with separate combination ORP electrode and temperature probe

54 21

shield

reference el.

glass el. +

í

aux. el.

8 7 4

2 1

5

Insulate!

combination
ORP electrode

Specify
temperature!

Fig. 17 ORP measurement with combination ORP electrode without temperature probe

Operation 20

3 Operation

User Interface

meas cal

conf

Stratos

cal

conf

Y

"

enter

Alarm LED

Keypad

Instrument designation

Rating plate

Status fields:

- Measuring mode

- Calibration mode

- Alarm (Contact only
for Model 2401)

-Wash contact active
(only Model 2401 pH)

- Configuration mode

Fig. 18 Front view of Stratos

cal

conf

"

Y

enter

cal

enter

➔

enter

conf

➔

Y

"

+

Operation 21

Display

Mode code

entry

Interval/

Response time

Hold state

active

Continue with

enter

Unit value symbols

Tempera-

ture

Loop

current

Alarm

setting

Senso­check



Calibration

Manual temp

specification

Sensor

data

Sensoface



Wait

Display/

Measured variable

Bar for
instrument status

Fig. 19 Stratos display

Keypad

Start, end calibration

Start, end configuration

Select digit position
(selected position flashes)

Change digit

Prompt in display:
continue in program sequence,
Configuration:

Confirm entries, next
configuration step,
Measuring mode:

Display output

current

Cal info, display asymmetry poten­tial (zero) and slope (see Pg. 33)

Error info, display last output error
message (see Pg. 33)

Start manual unit self-test
GainCheck



(see Pg. 22)

Y

"

+

Operation 22

Safety Functions

Sensoface electrode monitoring

Sensoface



provides information
on the electrode state. The asym­metry potential, slope and response
time during calibration are eva­luated. Sensocheck



continuously
monitors the glass and reference
electrode.

For more detailed information, see chapter “Diagnos-
tic, Maintenance and Cleaning” (Pg. 34).

GainCheck



manual self-test

Simultaneously pressing Y and "
starts the manual unit self-test.

A display test is carried out, the software version is
displayed and the memory and measured value
transmission are checked.

Automatic self-test

The automatic unit self-test checks the memory and
the measured-value transmission. It runs automati­cally in the background at fixed intervals.

Operation 23

Outputs

Loop current

The current loop transports power to and output sig­nals from the Stratos. The current is controlled by
the measured variable selected in the configuration.
The current beginning and end can be set to any
desired value.
To check connected peripherals (e.g. limit switches,
controllers), the loop current can be manually speci­fied (see Pg. 38).

HART communication

Stratos 2211 (X) pH can be remote controlled via
HART communication. It can be configured using a
handheld terminal or from the control room. Mea­sured values, messages and unit identification can
be downloaded at any time. This allows easy integra­tion also in fully automatic process sequences.

For more detailed information, refer to HART



Com-

mand Specification.

Alarm

During an error message the alarm LED flashes.
Alarm response time is permanently set to 10 s.

Error messages can also be signaled with a 22 mA
signal via the loop current (see Configuration,
Pg. 25).

conf

Operation 24

Configuration

Here the basic settings of the unit are carried out.
Symbols show which parameter is being configured.

Activate with conf
change parameter with Y and ",
confirm/continue with enter,
end configuration with conf

Mode code “1200”

During configuration the loop cur­rent is frozen
.

When the configuration mode is exited, the unit re­mains in the Hold state for safety reasons. This pre­vents undesirable reactions of the connected periph­erals (e.g. limit switches, controllers) due to incorrect
settings. The measured value and Hold are dis­played alternately. Now you can check whether the
measured value is plausible and specifically end the
Hold state with enter. After 20 sec. (measured
value stabilization) the Hold state is ended.

Operation 25

Configuration parameters

Before attempting any changes refer to the parameter setup list shown below. This table presents the possible options and the
factory settings.

Picto­graph

Parameter Choices Factory

Setting

Meas. variable (when changed,
complete configuration required)

pH 0.00 to 14.00
ORP –1,500 to 1,500 mV

pH

Temperature display /
detection

°C / °F
automatic detection

Auto °C

°C / °F

manual specification
°C/ °F
automatic detection
during measurement
manual specification
during calibration

T emperature probe Pt 100 / Pt 1000 /

NTC 30 kW

Pt 100

Current beginning,
current end

4 mA, 0 to 14 pH,
20 mA, 0 to 14 pH

4 mA, 0 pH
20 mA, 14 pH

Hold state Last: Last current value

Fix: Loop current specified

Last

22 mA signal for error message On / OFF OFF
Sensocheck



(sensor diagnostics)

On / OFF OFF

Calibration mode:
Automatic with Calimatic



BUF –00– Knick techn. buffers
BUF –01– Mettler Toledo techn. buffers
BUF –02– Merck/Riedel de Haën
BUF –03– Ciba (94)
BUF –04– Mettler Toledo (USA)
BUF –05– NIST standard buffers
BUF –06– HACH
BUF –07– WTW

BUF –01–

Manual MAN Manual buffer entry

DAT Data entry of premeasured values

Calibration timer interval 0,000 to 9,999 hours 0000 (OFF)

Note

cal

Note

cal

enter

Note

Operation 26

Calibration

You can conduct either a one or a two-point calibra­tion. The calibration can be carried out with the Cali­matic



automatic buffer recognition, with manual
buffer input or by entering pre-measured electrode
data.

With manual temperature specifica­tion, the temperature of the buffer
solutions must be entered in the
configuration prior to calibration.

Activate with cal
confirm/continue with enter,
abort with cal ➜ enter

During calibration the loop current
is frozen. The instrument is in the
Hold state.

When the calibration mode is exited, the Stratos re­mains in the Hold state for safety reasons. This pre­vents undesirable reactions of the connected periph­erals (e.g. limit switches, controllers) due to incorrect
settings. The measured value and Hold are dis­played alternately. Now you can check whether the
measured value is plausible and specifically end the
Hold state with enter or repeat calibration with cal.
If you end the Hold state, the Stratos will return to
measuring mode after 20 sec. (measured value sta­bilization).

Automatic calibration with Calimatic



BUF

and automatic calibration temp detection

The instrument can only operate
properly when the buffer solutions
used correspond to the configured
buffer set. Other buffer solutions,
even those with the same nominal
values, may demonstrate a different
temperature behavior. This leads to
measurement errors.

Activate calibration by pressing the
cal key.
Using the Y , " keys enter
mode code “1100” and then press
enter.

Remove electrode and temperature
probe and immerse them in the first
buffer solution; it does not matter
which buffer solution is taken first.

Start calibration with enter.

While the hour glass flashes, the
electrode and temperature probe
remain in the first buffer solution.

The response time of the electrode
and the temperature probe is con­siderably reduced if the electrode is
first moved about in the buffer solu­tion and then held still. Stirring pro­vides stable values faster.

Note

Note

cal

Operation 27

Buffer recognition

Nominal buffer value is displayed

Stability check:
measured mV value is displayed

The stability check can be aborted
with cal. However, accuracy of the
calibration will be compromised.

Calibration with the first buffer is
completed. Remove the electrode
and temperature probe from the
first buffer solution and rinse off
both thoroughly.

❏ If you would like to carry out a one-point calibra-

tion, end the calibration now with cal. The Stratos
then shows the newly determined asymmetry po­tential in the lower display and the old slope in the
main display.

❏ If you would like to carry out a two-point calibra-

tion, immerse the electrode and the temperature
probe in the second buffer solution. Now start the
calibration again with enter. The calibration pro­cess runs again as for the first buffer.

At the end of calibration the slope
and asymmetry potential (based on
25 °C) of the electrode are dis­played. Calibration is ended with
enter. The Stratos remains in the
Hold state. You can now reinstall
the electrode and the temperature
probe and end the Hold state with
enter. After 20 sec. (measured
value stabilization) the Stratos re­turns to measuring mode.

Automatic calibration with Calimatic



BUF

and manual specification of calibration temp

The instrument can only operate
properly when the buffer solutions
used correspond to the configured
buffer set. Other buffer solutions,
even those with the same nominal
values, may demonstrate a different
temperature behavior. This leads to
measurement errors.

Activate calibration by pressing the
cal key.
Using the Y , " keys enter
mode code “1100” and then press
enter.

Remove the electrode and immerse
it in the first buffer solution; it does
not matter which buffer solution is
taken first.
Enter the calibration temperature
using the Y and " keys.

enter

Note

Note

Operation 28

Start calibration with enter.

While the hour glass flashes, the
electrode remains in the first buffer
solution.

The response time of the electrode
is considerably reduced if the elec­trode is first moved about in the
buffer solution and then held still.
Stirring provides stable values
faster.

Buffer recognition
Nominal buffer value is displayed

Stability check:
measured mV value is displayed

The stability check can be aborted
with cal. However, accuracy of the
calibration will be compromised.

Calibration with the first buffer is
completed. Remove the electrode
from the first buffer solution and
rinse it off thoroughly.

❏ If you would like to carry out a one-point calibra-

tion, end the calibration now with cal. The Stratos
then shows the newly determined asymmetry po­tential in the lower display and the old slope in the
main display.

❏ If you would like to carry out a two-point calibra-

tion, immerse the electrode in the second buffer
solution. Now start the calibration again with enĆ
ter. The calibration process runs again as for the
first buffer.

At the end of calibration the slope
and asymmetry potential (based on
25 °C) of the electrode are dis­played. Calibration is ended with
enter. The Stratos remains in the
Hold state. You can now reinstall
the electrode and end the Hold
state with enter. After 20 sec.
(measured value stabilization) the
Stratos returns to measuring mode.

cal

Note

Note

Operation 29

Manual calibration MAN
with automatic calibration temp detection

(if selected in Conf mode)
For calibration with manual buffer specification, you

must enter the pH value of the buffer solution used in
the instrument for the proper temperature.
This enables calibration with any desired buffer solu­tion.

Activate calibration by pressing the
cal key.
Using the Y , " keys enter
mode code “1100” and then press
enter.

Remove electrode and temperature
probe and immerse them in the first
buffer solution; it does not matter
which buffer solution is taken first.
Confirm with enter.

Set the pH value of your buffer
solution for the proper temperature
with Y and ". Start calibration with
enter.

The response time of electrode and
temperature probe is considerably
reduced if the electrode is first
moved about in the buffer solution
and then held still.

Stability check: measured mV value
is displayed.

The stability check can be aborted
with cal. However, the calibration
accuracy will be compromised.

Calibration with the first buffer is
completed. Remove the electrode
and temperature probe from the
first buffer solution and rinse off
both thoroughly.

❏ If you would like to carry out a one-point calibra-

tion, press cal to end the calibration now . The
Stratos then shows the newly determined asym­metry potential (zero point) in the main display
and the old slope in the lower display.

❏ If you would like to carry out a two-point calibra-

tion, immerse the electrode in the second buffer
solution. Enter the pH value of the second buffer
solution as has been done with the first buffer.
Now start the calibration again with enter. The
calibration process runs again as for the first
buffer.

At the end of calibration the slope
and asymmetry potential (based on
25 °C) of the electrode are dis­played. Press enter to end calibra­tion. The Stratos remains in the
Hold state. You can now reinstall
the electrode and temperature
probe and end the Hold state with
enter. After 20 sec (measured
value stabilization) the Stratos re­turns to measuring mode.

cal

Note

Note

Operation 30

Manual calibration MAN
with manual specification of calibration temp

(if selected in Conf mode)
For calibration with manual buffer specification, you

must enter the pH value of the buffer solution used in
the instrument for the proper temperature.
This enables calibration with any desired buffer solu­tion.

Activate calibration by pressing the
cal key.
Using the Y , " keys enter
mode code “1100”and then press
enter.

Remove the electrode and immerse
it in the first buffer solution; it does
not matter which buffer solution is
taken first. Enter the calibration
temperature using the Y and "
keys and confirm with enter.

Set the pH value of your buffer
solution for the proper temperature
with Y and ". Start calibration with
enter.

The response time of electrode is
considerably reduced if the elec­trode is first moved about in the
buffer solution and then held still.

Stability check: measured mV value
is displayed.

The stability check can be aborted
with cal. However, the calibration
accuracy will be compromised.

Calibration with the first buffer is
completed. Remove the electrode
from the first buffer solution and
rinse it off thoroughly.

❏ If you would like to carry out a one-point calibra-

tion, press cal to end the calibration now . The
Stratos then shows the newly determined asym­metry potential (zero point) in the main display
and the old slope in the lower display.

❏ If you would like to carry out a two-point calibra-

tion, immerse the electrode in the second buffer
solution. Enter the pH value of the second buffer
solution as has been done with the first buffer.
Now start the calibration again with enter. The
calibration process runs again as for the first
buffer.

At the end of calibration the slope
and asymmetry potential (based on
25 °C) of the electrode are dis­played. Press enter to end calibra­tion. The Stratos remains in the
Hold state. You can now reinstall
the electrode and end the Hold
state with enter. After 20 sec.
(measured value stabilization) the
Stratos returns to measuring mode.

cal

Operation 31

Data entry of premeasured electrodes DAT

You can directly enter the slope and asymmetry po­tential of an electrode. The values must be known,
e.g. determined beforehand in the laboratory.

Activate calibration by pressing the
cal key.
Using the Y , " keys enter
mode code “1100”and then press
enter.

Enter asymmetry potential,
confirm with enter

Enter slope,
confirm with enter

At the end of calibration the slope
and asymmetry potential (based on
25 °C) of the electrode are dis­played. Press enter to end calibra­tion. The unit remains in the Hold
state. You can now reinstall the
electrode and the temperature
probe and end the Hold state with
enter. After 20 sec. (measured
value stabilization) the unit returns
to measuring mode.

Convert slope [%] to slope [mV/pH] at 25 °C

%

78 80 82 84 86 88 90 92 94 96 98 100 102

mV/pH 46.2 47.4 48.5 49.7 50.9 52.1 53.3 54.5 55.6 56.8 58.0 59.2 60.4

Note

cal

enter

Operation 32

Adjustment of temperature probe

This function should only be used
by experts. Incorrectly set parame­ters may go unnoticed, but change
the measuring properties.
Especially for Pt 100 temperature
probe, it is advisable to perform an
adjustment.

Activate calibration by pressing the
cal key.
Using the Y , " keys enter
mode code “1015” and then press
enter.

Measure the temperature of the
process medium using an external
thermometer.

Using the Y , " keys enter the de­termined temperature value in the
main display. If you take over the
temperature value shown in the
lower display , the correction is with­out effect.

Press enter to confirm the temper­ature value.

The Stratos remains in the Hold
state. You can end the Hold state
with enter. After 20 sec (measured
value stabilization) the Stratos re­turns to measuring mode.

Operation 33

Measurement

Measuring mode

In the measuring mode the main display shows the
configured measured variable (pH or mV) and the
secondary display the temperature.

Cal info

With cal and mode code “0000” you can activate the
cal info. Cal info shows the current calibration data
for approx. 20 sec. The 20 sec can be reduced by
pressing enter. During cal info the unit is not

in Hold

state.

Error info

With conf and mode code “0000” you can activate
the error info. Error info shows the most recent error
message for approx. 20 sec. After that the message
will be deleted. The 20 sec can be reduced by pres­sing enter. During error info the unit is not

in Hold

state.

Manual temperature specification

The

indicator signals that the temperature will be
manually specified. The measuring temperature can
be set in the configuration, the calibration tempera­ture in calibration.

Hold state

The unit will enter the Hold state under the following
conditions:

For calibration: Mode code 1015

Mode code 1100
Mode code 2222

configuration: Mode code 1200

Mode code 5555

The loop current is frozen at Last or Fix (configura­tion Pg. 25). If the calibration or configuration mode
is exited, the unit remains in the Hold state for safety
reasons. This prevents undesirable reactions of the
connected peripherals (e.g. limit switches, control­lers) due to incorrect settings. The measured value
and Hold are displayed alternately. Now you can
check whether the measured value is plausible and
specifically end the Hold state with enter. After 20
sec. (measured value stabilization) the unit returns to
measuring mode.

Note

Note

Troubleshooting, Cleaning 34

4 Diagnostics, Maintenance and Cleaning

Sensoface, Sensocheck



Sensoface provides information

on the electrode state. The slope,
asymmetry potential and response
time during calibration are eva­luated. Sensocheck



continuously
monitors the glass and reference
electrode. With Sensocheck



turned off no appears.

Three Smileys provide information on wear and re­quired maintenance. However, the unit can still de­termine the measured variable and output it via the
loop current.

The worsening of a Sensoface



cri­terion leads to the devaluation
or of the Sensoface indicator.

An improvement

of the Sensoface indicator

can only take place after calibration or removal of an
electrode defect. is only displayed when Senso-

check



has been activated.

The condition for accurate informa­tion is proper calibration.

Sensoface



displays during calibration

Display Problem Status

Electrode re­sponse time

The electrode adjusts slowly . You should consider replacing it. It may be
possible to achieve an improvement by cleaning or, in the case of an
electrode stored dry, by “watering”.

The electrode adjusts very slowly to the measured value. Correct mea­surement is no longer ensured. The electrode should be replaced.

Asymmetry
potential and

Asymmetry potential (zero point) and slope of the electrode are still
okay, however the electrode should be replaced soon.

slope

Asymmetry potential (zero point) and/or slope of the electrode have
reached values which no longer ensure proper calibration. It is advisable
to replace the electrode.

enter

conf

Troubleshooting, Cleaning 35

Sensoface



displays during measurement

Display Problem Status

Calibration

Over 80 % of the calibration interval has already past.

timer

The calibration interval has been exceeded.

Electrode
defect

Check the electrode and its connections (also see error messages 33
and 34).

Error Messages

When one of the following error messages is output,
the unit can no longer correctly determine the mea­sured variable or output it via the loop current.

During an error message the alarm LED flashes. The
alarm response time is permanently set to 10 sec.

During alarm condition the unit does not switch into
Hold state. The current loop will remain active and
still represents the currently displayed reading. If
22 mA function is configured (see page 25), error
messages will also be indicated with a 22 mA signal.

Error info

With conf and mode code “0000”
you can activate the error info. Er­ror info shows the most recent error
message for approx. 20 sec. After
that the message will be deleted.
The 20 sec can be reduced by
pressing enter. During error info
the unit is not

in Hold state.

Error
number

Display
(flashing)

Problem Possible causes

Err 01 pH electrode - Electrode defective

- Too little electrolyte in electrode

- Electrode not connected

- Break in electrode cable

- Incorrect electrode connected

- Measured pH value less than 0 or greater than +14

Err 02 Redox electrode - Electrode defective

- Electrode not connected

- Break in electrode cable

- Measured electrode voltage less than –1500 mV or
greater than +1500 mV

Troubleshooting, Cleaning 36

Error
number

Possible causesProblemDisplay

(flashing)

Err 03 T emperature probe - Incorrect temperature probe connected or configured

- Open or short circuit in temperature probe

- Measured temperature less than –20 °C or greater than
+150 °C (NTC 30 kW: +130 °C)

Err 21 Loop current - Measured value below configured current beginning

- Check configuration current beginning (see Pg. 25)

Err 22 Loop current - Measured value above configured current end

- Check configuration current end (see Pg. 25)

Err 23 Loop current - Configured current span too large or too small

(Difference between current beginning and end)

Err 33 Glass electrode - Glass electrode defective

- Connection cable or electrode cap defective

- Connection terminals or electrode cap dirty

Err 34 Reference elec-

trode

- Reference electrode defective

- Connection cable or electrode cap defective

- Connection terminals or electrode cap dirty

- Jumper between terminal 4 and 5 missing
(see Figs. 8a – 11 on Pg. 14 and the following)

Err 98 System error -Configuration or calibration data defective; completely

reconfigure and recalibrate the unit

- Measured value transmission defective

- Memory error in unit program (PROM defective)

Err 99 Factory settings -EEPROM or RAM defective,

- Error in factory settings

This error message normally should not occur, as the
data are protected from loss by multiple safety functions.
Should this error message nevertheless occur, there is

no remedy. The unit must be repaired and recalibrated at

the factory.

Troubleshooting, Cleaning 37

Calibration Error Messages

(only during calibration)

Display

Problem Possible causes
Asymmetry poten-

tial (zero) out of
range 〈±60 mV)

- Electrode “worn out”

- Buffer solutions contaminated

- Buffer does not belong to configured buffer set

- Temperature probe not immersed in buffer solution (for automatic
temperature compensation)

- Wrong buffer temperature set (for manual temperature specifica­tion)

- Electrode with nominal zero point < pH 6 or > pH 8 is used

Electrode slope
out of range

(80 – 103 %)

- Electrode “worn out”

- Buffer solutions contaminated

- Buffer does not belong to configured buffer set

- Temperature probe not immersed in buffer solution (for automatic
temperature compensation)

- Wrong buffer temperature set (for manual temperature specifica­tion)

- Electrode used has different nominal slope

Problems during
recognition of the
buffer solution

- Same or similar buffer solution was used for both calibration steps

- Buffer solution used does not belong to buffer set currently config­ured in the unit

- During manual calibration the buffer solutions were not used in the
specified order

- Buffer solutions contaminated

- Electrode defective

- Electrode not connected

- Electrode cable defective

- Wrong buffer temperature set (for manual temperature specifica­tion)

Calibration was
canceled after
approx. 2 minutes,
because the elec­trode drift was too
large.

- Electrode defective or dirty

- No electrolyte in the electrode

- Electrode cable insufficiently shielded or defective

- Strong electric fields influence the measurement

- Major temperature fluctuation of the buffer solution

- No buffer solution or extremely diluted

Warning

Troubleshooting, Cleaning 38

Diagnostics Functions

Cal info

Pressing cal and entering mode code “0000” is go­ing to activate the cal info. Cal info shows the current
calibration data for approx. 20 sec. During cal info
the unit is not

in Hold state.

Error info

Pressing conf and entering mode code “0000” is
going to activate the error info. Error info shows the
most recent error message for approx. 20 sec. After
that the message will be deleted. The 20 sec can be
reduced by pressing enter. During error infothe in­strument is not

in Hold state.

Display electrode potential

During electrode maintenance it is useful to directly
indicate the electrode potential. This allows, for ex­ample, to check electrode response after cleaning.

Pressing cal and entering mode code “2222” will
display the electrode potential. The instrument is in
Hold state.

Display loop current

Pressing enter in measuring mode displays the
loop current for a few seconds.

Current source

To check the connected peripherals (e.g. limit
switches, controllers), the loop current can be manu­ally specified.

In the current source function the
loop current no longer follows the
measured value! It is manually spe­cified.
Therefore, it must be ensured that
the connected devices (control
room, controllers, indicators) do not
interpret the current value as a
measured value!

Pressing conf and entering mode code “5555” you
enter the current source mode. Specify the loop cur­rent using ", Y and enter. The present loop cur­rent is shown in the lower display.
Pressing conf exits the current source mode again.

GainCheck



manual unit self-test

To start press Y and " simultaneously.
A display test is carried out, the software version is

displayed and the memory and measured-value
transmission checked.

Automatic unit self-test

The automatic unit self-test checks the memory and
the measured-value transmission. It runs automati­cally in the background at fixed intervals.

Troubleshooting, Cleaning 39

Maintenance and Cleaning

Maintenance

The Stratos 2201/221 1 (X) pH contains no user re­pairable components. If problems persist even after
reviewing section 4, please contact the factory.

Cleaning

To remove dust, dirt and spots, the external surfaces
of the unit may be wiped with a damp, lint-free cloth.
A mild household cleaner may also be used if neces­sary.

Specifications 40

5 Annex

Product Line

Units

Ref. No.

Stratos 2201 pH 2201 pH
Stratos 2201 X pH for application

in hazardous areas

2201 X pH

Stratos 2211 pH
with HART



communication

2211 pH

Stratos 2211 X pH
with HART



communication, for

application in hazardous areas

2211 X pH

Mounting Accessories

Ref. No.

Pipe-mount kit ZU 0274
Panel-mount kit ZU 0275
Protective hood ZU 0276

Further Accessories

Ref. No.

HART



test socket, integrated in
Pg cable gland
(for Stratos 2211 (X) pH only)

ZU 0287

SMEK input socket
(for sensor cable with one coax
line)

ZU 0322

Suggested Power Supplies

Ref. No.

Power supply / isolator for
24 Vac/dc

WG 20 A2

Repeater power supply for
90 - 253 Vac

WG 21 A7

for 24 Vac/dc WG 21 A7

Opt. 336

with HART



communication

WG 21 A7

Opt. 470

Loop-powered supply with
HART



communication

WG 25 A7

Specifications 41

Specifications

Stratos 2201 pH / 2211 pH
pH/mV input

Ranges pH value 0.00 to +14.00

mV value –1500 to +1500 mV

Glass

input resistance > 0.5

*

1012 W

input current (20 °C)

1)

< 2*10

–12

A

Reference

input resistance > 1

*

1010 W

input current (20 °C)

1)

< 1*10

–10

A

Meas. Error
(+ 1 count)

pH value < 0.02
mV < 1 mV

Electrode
monitoring

Sensocheck: Monitoring of glass
and reference electrode
(can be switched off)

Alarm
Limits

Determination during calibration

Electrode
Standardiza­tion

*)

– Calimatic automatic calibration

with the buffer sets:

-00- Knick technical buffers

-01- (correspond to Mettler
Toledo techn. buffers)

2.00/4.01/7.00/9.21

-02- Merck/Riedel de Haën

2.00/4.00/7.00/9.00/12.00

-03- Ciba (94)

2.06/4.00/7.00/10.00

-04- Mettler Toledo (USA)

4.00/7.00/10.01

-05- Standard buffers NIST

4.006/6.865/9.180

-06- HACH

4.00/7.00/10.18

-07- WTW techn. buffers

2.00/4.01/7.00/10.00

Stratos 2201 X pH / 2211 X pH
pH/mV input EEx ia IIC

Ranges pH value 0.00 to +14.00

mV value –1500 to +1500 mV

Glass

input resistance > 0.5

*

1012 W

input current (20 °C)

1)

< 2*10

–12

A

Reference

input resistance > 1

*

1010 W

input current (20 °C)

1)

< 1*10

–10

A

Meas. Error
(+ 1 count)

pH value < 0.02
mV < 1 mV

Electrode
monitoring

Sensocheck: Monitoring of glass
and reference electrode
(can be switched off)

Alarm
Limits

Determination during calibration

Electrode
Standardiza­tion

*)

– Calimatic automatic calibration

with the buffer sets:

-00- Knick technical buffers

-01- (correspond to Mettler
Toledo techn. buffers)

2.00/4.01/7.00/9.21

-02- Merck/Riedel de Haën

2.00/4.00/7.00/9.00/12.00

-03- Ciba (94)

2.06/4.00/7.00/10.00

-04- Mettler Toledo (USA)

4.00/7.00/10.01

-05- Standard buffers NIST

4.006/6.865/9.180

-06- HACH

4.00/7.00/10.18

-07- WTW techn. buffers

2.00/4.01/7.00/10.00

Specifications 42

Stratos 2201 pH / 2211 pH

– Manual entry of individual

buffer values (MAN)

– Data entry for pre-measured

electrodes (DAT)

– Temperature probe adjustment

Calibration
Timer

0 to 9999 h

Calibration
Ranges

asymmetry potential ± 60 mV
slope 80 to 103 %
For values outside this range, display
message (Sensoface



)

Temp Input

Pt 100 / Pt 1000 / NTC 30 kW

Ranges

NTC –20.0 to +130.0 °C

–4 to +266 °F

Pt –20.0 to +150.0 °C

–4 to 302 °F

Meas. Error

< 0.5 K

2)

± 1 count

T emp Com­pensation

automatic with Pt 100 / Pt 1000 /
NTC 30 kW or manual

Display

LC display, alarm LED

Loop
Current

4 to 20 mA, floating
22 mA for error message

*)

supply voltage 12 to 30 V

Current Error

< 0.3 % of current value ± 50 mA

Current
Source

3.80 mA to 22.00 mA

Start/End of
Scale

*)

as desired within pH or mV ranges

Spans

*)

pH value 2.00 to 14.00
mV value 200 to 3000 mV

Stratos 2201 X pH / 2211 X pH

– Manual entry of individual

buffer values (MAN)

– Data entry for pre-measured

electrodes (DAT)

– Temperature probe adjustment

Calibration
Timer

0 to 9999 h

Calibration
Ranges

asymmetry potential ± 60 mV
slope 80 to 103 %
For values outside this range, display
message (Sensoface



)

Temp Input

Pt 100 / Pt 1000 / NTC 30 kW
EEx ia IIC

Ranges

NTC –20.0 to +130.0 °C

–4 to +266 °F

Pt –20.0 to +150.0 °C

–4 to 302 °F

Meas. Error

< 0.5 K

2)

± 1 count

T emp Com­pensation

automatic with Pt 100 / Pt 1000 /
NTC 30 kW or manual

Display

LC display, alarm LED

Loop
Current

EEx ib IIC

4 to 20 mA, floating
22 mA for error message

*)

supply voltage 12 to 30 V
I

max

= 100 mA, P

max

= 0.8 W

Current Error

< 0.3 % of current value ± 50 mA

Current
Source

3.80 mA to 22.00 mA

Start/End of
Scale

*)

as desired within pH or mV ranges

Spans

*)

pH value 2.00 to 14.00
mV value 200 to 3000 mV

Specifications 43

Stratos 2201 pH / 2211 pH
HART



Com-

munication

(Model 2211
only)

digital communication via FSK modu­lation of loop current,
point-to-point connection,
reading of device identification, mea­sured values, status and messages
reading and writing of parameters

Explosion
Protection

–

Data
Retention

> 10 years (EEPROM)

EMC Emitted interference:

EN 61 326 Class B
Immunity to interference:
EN 61 326, EN 61 326/A1

Temperature Operating/environmental temp

–20 to +55 °C
Transport and storage temp
–20 to +70 °C

Enclosure Material: thermoplastic polyester , re-

inforced (polybutylene terephthalate)
Protection: IP 65
Color: bluish gray RAL 7031

Cable Glands 3 Pg 13.5 threaded cable glands

(not mounted),
up to 5 Pg threaded cable glands
possible (only use plastic glands)

Dimensions See Dimension drawings, Pg. 9 ff

Weight

approx. 1 kg

*) user defined 1) doubles every 10 K

2) Pt 100: 1K

Stratos 2201 X pH / 2211 X pH
HART



Com-

munication

(Model 2211X
only)

digital communication via FSK modu­lation of loop current,
point-to-point connection,
reading of device identification, mea­sured values, status and messages
reading and writing of parameters

Explosion
Protection

II 2 G EEx ib [ia] IIC T6
CE 0032 TÜV 99 ATEX 1446

Data
Retention

> 10 years (EEPROM)

EMC Emitted interference:

EN 61 326 Class B
Immunity to interference:
EN 61 326, EN 61 326/A1

Temperature Operating/environmental temp

–20 to +55 °C
Transport and storage temp
–20 to +70 °C

Enclosure Material: thermoplastic polyester , re-

inforced (polybutylene terephthalate)
Protection: IP 65
Color: bluish gray RAL 7031

Cable Glands 3 Pg 13.5 threaded cable glands

(not mounted),
up to 5 Pg threaded cable glands
possible (only use plastic glands)

Dimensions See Dimension drawings, Pg. 9 ff

Weight

approx. 1 kg

*) user defined 1) doubles every 10 K

2) Pt 100: 1K

Specifications 44

EC-T ype-Examination Certificate

Specifications 45

Specifications 46

Specifications 47

Declaration of conformity

Buffer Charts 48

Buffer Charts

-00- Knick technical buffers

-01- (correspond to Mettler-Toledo technical buffers)

°CpH

0

2.03 4.01 7.12 9.52

5 2.02 4.01 7.09 9.45
10 2.01 4.00 7.06 9.38
15 2.00 4.00 7.04 9.32
20 2.00 4.00 7.02 9.26

25 2.00 4.01 7.00 9.21

30 1.99 4.01 6.99 9.16
35 1.99 4.02 6.98 9.11
40 1.98 4.03 6.97 9.06
45 1.98 4.04 6.97 9.03
50 1.98 4.06 6.97 8.99
55 1.98 4.08 6.98 8.96
60 1.98 4.10 6.98 8.93
65 1.99 4.13 6.99 8.90
70 1.99 4.16 7.00 8.88
75 2.00 4.19 7.02 8.85
80 2.00 4.22 7.04 8.83
85 2.00 4.26 7.06 8.81
90 2.00 4.30 7.09 8.79
95 2.00 4.35 7.12 8.77

-02- Merck-Titrisols, Riedel Fixanals
°CpH

0

2.01 4.05 7.13 9.24 12.58

5 2.01 4.04 7.07 9.16 12.41
10 2.01 4.02 7.05 9.11 12.26
15 2.00 4.01 7.02 9.05 12.10

20 2.00 4.00 7.00 9.00 12.00

25 2.00 4.01 6.98 8.95 11.88
30 2.00 4.01 6.98 8.91 11.72
35 2.00 4.01 6.96 8.88 11.67
40 2.00 4.01 6.95 8.85 11.54
45 2.00 4.01 6.95 8.82 11.44
50 2.00 4.00 6.95 8.79 11.33
55 2.00 4.00 6.95 8.76 11.19
60 2.00 4.00 6.96 8.73 11.04
65 2.00 4.00 6.96 8.72 10.97
70 2.01 4.00 6.96 8.70 10.90
75 2.01 4.00 6.96 8.68 10.80
80 2.01 4.00 6.97 8.66 10.70
85 2.01 4.00 6.98 8.65 10.59
90 2.01 4.00 7.00 8.64 10.48
95

2.01 4.00 7.02 8.64 10.37

-03- Ciba (94) buffers
Nominal values: 2.06, 4.00, 7.00, 10.00
°CpH

0

2.04 4.00 7.10 10.30

5 2.09 4.02 7.08 10.21
10 2.07 4.00 7.05 10.14
15 2.08 4.00 7.02 10.06
20 2.09 4.01 6.98 9.99
25 2.08 4.02 6.98 9.95
30 2.06 4.00 6.96 9.89
35 2.06 4.01 6.95 9.85
40 2.07 4.02 6.94 9.81
45 2.06 4.03 6.93 9.77
50 2.06 4.04 6.93 9.73
55 2.05 4.05 6.91 9.68
60 2.08 4.10 6.93 9.66
65 2.07* 4.10* 6.92* 9.61*
70 2.07 4.11 6.92 9.57
75 2.04* 4.13* 6.92* 9.54*
80 2.02 4.15 6.93 9.52
85 2.03* 4.17* 6.95* 9.47*
90 2.04 4.20 6.97 9.43
95 2.05* 4.22* 6.99* 9.38*

* extrapolated

-04- Mettler Toledo (USA)
°CpH

0

4.00 7.12 10.32

5 4.00 7.09 10.25
10 4.00 7.06 10.18
15 4.00 7.04 10.12
20 4.00 7.02 10.06

25 4.00 7.00 10.01

30 4.01 6.99 9.97
35 4.02 6.98 9.93
40 4.03 6.98 9.89
45 4.04 6.97 9.86
50 4.06 6.97 9.83
55 4.06

*

6.97

*

9.83

*

60 4.06

*

6.97

*

9.83

*

65 4.06

*

6.97

*

9.83

*

70 4.06

*

6.97

*

9.83

*

75 4.06

*

6.97

*

9.83

*

80 4.06

*

6.97

*

9.83

*

85 4.06

*

6.97

*

9.83

*

90 4.06

*

6.97

*

9.83

*

95 4.06

*

6.97

*

9.83

*

* extrapolated

Buffer Charts 49

-05- NIST standard-buffers
°CpH

0

4.010 6.984 9.464

5 4.004 6.951 9.395
10 4.000 6.923 9.332
15 3.999 6.900 9.276
20 4.001 6.881 9.225

25 4.006 6.865 9.180

30 4.012 6.853 9.139
35 4.021 6.844 9.102
40 4.031 6.838 9.068
45 4.043 6.834 9.038
50 4.057 6.833 9.011
55 4.071 6.834 8.985
60 4.087 6.836 8.962
65 4.109 6.841 8.942
70 4.126 6.845 8.921
75 4.145 6.852 8.903
80 4.164 6.859 8.885
85 4.185 6.868 8.868
90 4.205 6.877 8.850
95

4.227 6.886 8.833

-06- HACH buffers
Nominal values: 4.00, 7.00, 10.18
°CpH

0

4.00 7.14 10.30

5 4.00 7.10 10.23
10 4.00 7.04 10.11
15 4.00 7.04 10.11
20 4.00 7.02 10.05
25 4.01 7.00 10.00
30 4.01 6.99 9.96
35 4.02 6.98 9.92
40 4.03 6.98 9.88
45 4.05 6.98 9.85
50 4.06 6.98 9.82
55 4.07 6.98 9.79
60 4.09 6.99 9.76
65 4.09

*)

6.99

*)

9.76

*)

70 4.09

*)

6.99

*)

9.76

*)

75 4.09

*)

6.99

*)

9.76

*)

80 4.09

*)

6.99

*)

9.76

*)

85 4.09

*)

6.99

*)

9.76

*)

90 4.09

*)

6.99

*)

9.76

*)

95 4.09

*)

6.99

*)

9.76

*)

* values complemented
Buffer values up to 60 °C as specified by Bergmann & Beving Process

AB.

-07- WTW technical buffers
°C ST 1 ST 2 ST 3 ST 5

0

2.03 4.01 7.12 10.65

5 2.02 4.01 7.09 10.52
10 2.01 4.00 7.06 10.39
15 2.00 4.00 7.04 10.26
20 2.00 4.00 7.02 10.13

25 2.00 4.01 7.00 10.00

30 1.99 4.01 6.99 9.87
35 1.99 4.02 6.98 9.74
40 1.98 4.03 6.97 9.61
45 1.98 4.04 6.97 9.48
50 1.98 4.06 6.97 9.35
55 1.98 4.08 6.98
60 1.98 4.10 6.98
65 1.99 4.13 6.99
70 2.00 4.16 7.00
75 2.00 4.19 7.02
80 2.00 4.22 7.04
85 2.00 4.26 7.06
90 2.00 4.30 7.09
95

2.00 4.35 7.12

Asymmetry
potential
(zero point)

Buffer set

Buffer
solution

cal

Calibration

Calibration
buffer set

Calimatic



Combination
electrode

conf

Electrode
slope

Electrode zero
point

GainCheck



HART



T echnical Terms 50

Technical Terms

The voltage which a pH electrode
gives off at a pH of 7. The asymme­try potential is different for every
electrode and changes with age
and wear.

Contains selected buffer solutions
which can be used for automatic
calibration with the Knick Cali­matic



. The buffer set must be se-

lected prior to calibration.

Solution with an exactly defined pH
value for calibrating a pH meter.

Key for activating and ending cal­ibration.

Adjustment of the pH meter to the
current electrode characteristics.
The asymmetry potential (zero
point) and slope are adjusted. Ei­ther a one-or two-point calibration
can be carried out. With one-point
calibration only the asymmetry po­tential is adjusted.

See Buffer set.

Automatic buffer recognition. Be­fore the first calibration, the buffer
set used must be activated once.

The patented Calimatic



then auto­matically recognizes the buffer solu­tion used during calibration.

Combination of glass and reference
electrode in one body.

Key for starting and ending configu­ration.

Is indicated in % of the theoretical
slope (59.2 mV/pH at 25 °C). The
electrode slope is different for every
electrode and changes with age
and wear.

See Asymmetry potential.

Unit self-test which runs automati­cally in the background at fixed in­tervals. The memory and mea­sured-value transmission are
checked. Y ou can also start the
GainCheck



manually (see Pg. 22).
Then a display test is also con­ducted and the software version
displayed.

Highway Addressable Remote
Transducer , digital communication

via FSK modulation of the loop cur­rent

Mode code

One-point
calibration

pH electrode
system

Response
time

Sensocheck



Sensoface



Slope

Two-point
calibration

Zero point

T echnical Terms 51

Preset four-digit number to select
certain modes.

Calibration with which only the elec­trode asymmetry potential (zero
point) is taken into consideration.
The previous slope value is re­tained. Only one buffer solution is
required for a one-point calibration.

A pH electrode system consist of a
glass and a reference electrode. If
they are combined in one body,
they are referred to as a combina­tion electrode.

Time from the start of a calibration
step to the stabilization of the elec­trode potential.

Sensocheck



continuously moni­tors the glass and reference elec­trodes.

provides information on the status
of the electrode. The zero point,
slope and response time are eva­luated. The glass and reference
electrodes are continuously moni­tored.

See Electrode slope.

Calibration with which the electrode
asymmetry potential (zero point)
and slope are determined. Two
buffer solutions are required for
two-point calibration.

See Assymmetry potential.

Index 52

Index

, 34

22 mA signal for alarm, 23, 35

configuring, 25

A

Alarm, 23

response time, 35
Alarm LED, 35
Alarm via loop current, 23, 35

configuring, 25
Assembly, 8
Asymmetry potential

definition, 50

display , 38
Automatic calibration

with automatic cal temp detec-

tion, 26

with manual cal temp, 27

B

Buffer charts, 48
Buffer set

definition, 50

selecting, 25
Buffer solution, definition, 50

C

Cal info, 33, 38

Calibration, 26

automatic

with automatic cal temp

detection, 26

with manual cal temp, 27

Calimatic

with automatic cal temp

detection, 26

with manual cal temp, 27
data entry, 31
definition, 50
manual

with automatic cal temp

detection, 29

with manual cal temp, 30
temp probe adjustment, 32

Calibration buffer set, definition,
50

Calibration data, display, 38
Calibration error messages, 37
Calibration mode, configuring, 25
Calibration timer interval, configur-

ing, 25
Calimatic, definition, 50
Certificate of Conformity, 44
Cleaning, 39
Combination electrode, definition,

50
Configuration, 24

Connecting

handheld terminal, 11

lines, 11
Connecting cable, fixing, 11
Current source, 38

D

Declaration of Conformity, 47
Diagnostics functions, 38
Dimension drawings, 9
Display , 21

E

Electrode monitoring, Sensoface,
22, 34

Electrode potential, display, 38
Electrode slope

definition, 50

display , 38
Electrode zero point, definition, 50
Error info, 33, 35, 38
Error message, last, 33, 35, 38
Error message via loop current,

23, 35

configuring, 25
Error messages, 35–38

G

GainCheck, 22, 38

definition, 50

Index 53

H

HART, definition, 50
HART communication, 23
Hold mode, 33

I

Input voltage, display, 38
Installation, 13

K

Keypad, 21

L

Loop current, 23

configuring, 25
display , instantaneous, 38
frozen, 33
Hold state, 25

M

Maintenance, 39
Manual calibration

with automatic cal temp detec­tion, 29
with manual cal temp, 30

Manual temperature specification,
33

Measured variable, configuring,
25

Measuring mode, 33

Messages, Sensoface, 34
Mode code, 6

definition, 51
Mounting diagram, 9
mV measurement, 33

O

One–point calibration, 27, 28, 29,
30

definition, 51
ORP measurement, 19
Outputs, 23

P

Packing list, 8
pH electrode system, definition,

51
pH measurement, 33
Pipe mount kit, 10
Product line, 40
Protective hood, 10

R

Response time, definition, 51

S

Safety precautions, 5

Self–test

automatic, 38
manual, 22, 38

Sensocheck, 34

definition, 51
on or off, 25

Sensoface, 22

definition, 51
diagnostics, 34
messages, 34

Slope

definition, 51

display , 38
Smiley, 34
Software version, display, 22, 38
Specifications, 41
Stripping lengths, 11

T

Technical terms, 50
Temp probe adjustment, 32
T emperature detection, configur-

ing, 25
Terminals, pulling out, 11
Two–point calibration, 29, 30

definition, 51
Type Examination Certificate, 44

U

Unit self–test, automatic, 22
User Interface, 20

Index 54

W

Wiring

ORP measurement, 19
pH measurement, 14

Z

Zero point, definition, 51