PCE Instruments PCE-MWM 2, PCE-MWM 200, PCE-MWM 230, PCE-MWM 240B, PCE-MWM 220 Series Manual

Moisture Sensor PCE-MWM 2xx

Manual

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Last change: 27 March 2018

v1.41

English

Manual

Table of Contents

1 Introduction ..................................................................................................................... 5

2 Safety notes ..................................................................................................................... 5

3 Scope of delivery ............................................................................................................. 5

4 Specifications .................................................................................................................. 6

5 Mechanical installation ................................................................................................... 7

5.1 PCE-MWM 210 ........................................................................................................ 7

5.1.1 Flange ........................................................................................................... 8

5.1.2 Installation ..................................................................................................... 9

5.1.3 Sensor Coverage ........................................................................................ 10

5.2 PCE-MWM 240A .................................................................................................... 11

5.2.1 Dimensions of the base plate of the sensor ................................................. 11

5.2.2 Installation with welds ................................................................................. 12

5.2.3 Installation with screws ............................................................................... 13

5.2.4 Installation with flange ................................................................................. 14

5.2.5 Installation on curved surfaces .................................................................... 15

5.2.6 Sensor coverage ......................................................................................... 16

5.3 PCE-MWM 240B .................................................................................................... 17

5.3.1 Sensor coverage ......................................................................................... 19

6 Electrical installation ..................................................................................................... 20

6.1 Cabling .................................................................................................................. 20

6.1.1 General properties ...................................................................................... 20

6.1.2 Power supply .............................................................................................. 20

6.1.3 Communication ........................................................................................... 23

6.2 Analog output ....................................................................................................... 25

6.2.1 Connection .................................................................................................. 25

6.3 RS-485 interface ................................................................................................... 26

6.3.1 Connection .................................................................................................. 26

6.3.2 Protocol....................................................................................................... 26

7 PCE-MWM Manager ....................................................................................................... 28

7.1 Introduction .......................................................................................................... 28

7.2 Overview PCE-MWM Manager ............................................................................. 29

7.3 Connection electronic unit .................................................................................. 30

7.4 Initial calibration ............................................................................................. 31

7.5 Calibration ..................................................................... 33

7.5.1 Create new calibration ........................................................................... 33

7.5.2 Calibration table .......................................................................................... 33

7.5.3 Evaluate calibration ..................................................................................... 37

7.5.4 Finish calibration ......................................................................................... 38

Manual

7.6 Transfer calibration to / from electronic unit ............................................ 38

7.7 Export / import calibration in .csv-file ...................................................... 40

7.8 Select calibration in electronic unit ............................................................... 40

7.9 Establish / close connection ..................................................................... 40

7.10 Test ................................................................ ............................................. 40

7.11 Settings ........................................................................................................... 40

7.12 Configuration electronic unit ......................................................................... 41

7.13 Language ........................................................................................................ 41

8 Appendix ........................................................................................................................ 42

8.1 Notes for gathering and handling of samples .................................................... 42

8.2 Determining moisture content of samples ......................................................... 42

8.2.1 Drying oven ................................................................................................. 42

8.2.2 Moisture analyzer ........................................................................................ 43

9 Contact ........................................................................................................................... 44

Manual

Table of figures

Fig. 1 Installation of PCE-MWM 210 ................................................................................................................................. 7

Fig. 2 Welding flange ........................................................................................................................................................ 8

Fig. 3 Clamping ring .......................................................................................................................................................... 8

Fig. 4 Sensor fixed in ring-assembly ................................................................................................................................. 9

Fig. 5 Ring-assembly ........................................................................................................................................................ 9

Fig. 6 Distance of PCE-MWM 210 to metallic components ............................................................................................ 10

Fig. 7 Dimensions of the base plate of the moisture sensor PCE-MWM 240A .............................................................. 11

Fig. 8 Dimensions of the rectangular cut-out .................................................................................................................. 12

Fig. 9 Installation with welds ........................................................................................................................................... 12

Fig. 10 Dimensions of the rectangular cut-out ................................................................................................................ 13

Fig. 11 Installation with screws ....................................................................................................................................... 13

Fig. 12 Dimensions of the rectangular cut-out ................................................................................................................ 14

Fig. 13 Dimensions of the flange for installation of the moisture sensor PCE-MWM 240A ............................................ 14

Fig. 14 Installation on a curved surface .......................................................................................................................... 15

Fig. 15 Sufficient material coverage of the moisture sensor PCE-MWM 240A .............................................................. 16

Fig. 16 Insufficient material coverage of the moisture sensor PCE-MWM 240A ............................................................ 16

Fig. 17 Components of the moisture sensor PCE-MWM 240B ...................................................................................... 17

Fig. 18 Dimensions of the welding flanges ..................................................................................................................... 17

Fig. 19 Installation of the moisture sensor PCE-MWM 240B .......................................................................................... 18

Fig. 20 Sufficient material coverage of the moisture sensor PCE-MWM 240B .............................................................. 19

Fig. 21 Insufficient material coverage of the moisture sensor PCE-MWM 240B ............................................................ 19

Fig. 22 M12 connector .................................................................................................................................................... 21

Fig. 23 Wiring diagram .................................................................................................................................................... 21

Fig. 24 Pin assignment .................................................................................................................................................... 21

Fig. 25 Core identification code....................................................................................................................................... 22

Fig. 26 Pin assignment for power supply ........................................................................................................................ 22

Fig. 27 M12 connector .................................................................................................................................................... 23

Fig. 28 Wiring diagram .................................................................................................................................................... 23

Fig. 29 Pin assignment .................................................................................................................................................... 24

Fig. 30 Core identification code....................................................................................................................................... 24

Fig. 31 Pin assignment for signal output ......................................................................................................................... 24

Fig. 32 Pin assignment for analog output ....................................................................................................................... 25

Fig. 33 Pin assignment for serial port RS-485 ................................................................................................................ 26

Fig. 34 Calibration curves for different material .............................................................................................................. 28

Fig. 35 PCE-MWM Manager main window ..................................................................................................................... 29

Fig. 36 Configuring RS-485 converter ............................................................................................................................ 30

Fig. 37 Settings ............................................................................................................................................................... 31

Fig. 38 Successful connection ........................................................................................................................................ 31

Fig. 39 Message about missing initial calibration............................................................................................................ 31

Fig. 40 Configuration electronic unit ............................................................................................................................... 32

Fig. 41 Dialog for initial calibration .................................................................................................................................. 32

Fig. 42 Initial calibration successful ................................................................................................................................ 32

Fig. 43 Tree view of calibrations ..................................................................................................................................... 33

Fig. 44 Window for new calibration ................................................................................................................................. 33

Fig. 45 Calibration table .................................................................................................................................................. 34

Fig. 46 Warning if measured temperature of recorded date exceeds threshold ............................................................. 34

Fig. 47 Calibration table with first entry ........................................................................................................................... 35

Fig. 48 Assign moisture to sensor data ........................................................................................................................... 35

Fig. 49 Calibration table with multiple measurements .................................................................................................... 36

Fig. 50 Calibration with high accuracy ............................................................................................................................ 37

Fig. 51 Calibration with reduced accuracy ...................................................................................................................... 37

Fig. 52 Flawed calibration ............................................................................................................................................... 38

Fig. 53 Transfer calibration to electronic unit .................................................................................................................. 38

Fig. 54 Transfer best-fit line from electronic unit ............................................................................................................. 39

Fig. 55 Imported best-fit line from electronic unit displayed in the tree view .................................................................. 39

Fig. 56 Currently selected calibration in the electronic unit ............................................................................................ 40

Fig. 57 Status bar for Test ............................................................................................................................................... 40

5

1 Introduction

This manual as well as the technical description is both intended to introduce the user to the operating principle,
installation and calibration of the moisture sensor. The manufacturer reserves the right to change the design and
circuitry of the moisture sensor.

2 Safety notes

Please read this manual carefully and completely before you attempt to use the device for the first time. The device
may only be used by qualified personnel and repaired by PCE Instruments personnel. Damages or injuries caused by
non-observance of this manual are not covered by warranty.

 Only use the moisture sensor PCE-MWM 200 Series when the 24 V power supply is grounded
 Do not use the moisture sensor if the electronic unit cover has been removed
 Only open the cover of the electronic unit after the power supply was disconnected
 Do not open the sensor case
 All types of maintenance, repair and installation including disconnection, swapping wires as well as

dismounting, should only be done when the device is disconnected from the power supply

 Do not operate the moisture sensor if the cables, plugs or the power supply are damaged
 Operation of the sensor system is only permitted in the approved temperature range
 Technical changes of the device are prohibited
 The sensor system should only be cleaned with a damp cloth and only ph-neutral cleaners may be used

This manual is published by PCE Instruments without any guarantee.
We explicitly refer to our general warranty terms which can be found in our general terms of business.
Please contact PCE instruments if you have any questions.

3 Scope of delivery

 1 x PCE-MWM 2xx sensor
 2 x 5 m cables
 1 x CD (PC software, manual)
 1 x RS-485 / USB converter

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4 Specifications

PCE-MWM

200/230/240A/

240B

PCE-MWM 220

PCE-MWM 210

Sensor

Measuring range

0 … 100 %

Absolute error of moisture
measurement

see Table 1

Calibration temperature range

+5 … +80 °C

Measuring range temperature

-20 … +145 °C

Measuring interval

1 second

Dimensions

Length 240B:

200 … 1500 mm

Length x Width:

270 x 290 mm

Length x Ø:

103 x 108 mm

Weight

Ca. 9 kg

Protection class

IP67, GOST 14254-96

Cable length

1.5 … 4 m

Electronic unit

Dimensions (L x W x H)

255 x 170 x 60 mm

Weight

2 kg

Protection class

IP54, GOST 14254-96

Operating temperature

+5 … +60 °C

Output interface

Serial interface: RS-485 MODBUS RTU

Current loop: 4 … 20 mA

Power supply

Nominal voltage: 24 V

Permissible voltage: 18 … 36 V

Current draw

Max. 200 mA

Max. length of cable

RS-485 to external control device
(controller / computer)

1000 m

Max. length of cable

4 … 20 mA analog signal from
electronic unit to external display

100 m

Average life

10 years

Inline measurement (PCE-MWM 220 only)

Nominal size of pipe

DN50, DN80, DN125

Max. overpressure

10 MPa

PCE-MWM 200/230/240A/240B

PCE-MWM 220

PCE-MWM 210

Moisture [%]

Min. error

(absolute) [%]

Moisture [%]

Min. error

(absolute) [%]

Moisture [%]

Min. error

(absolute) [%]

0 … 6

0.3

0 … 0,3

0.03

Up to 10

0.5

6 … 8

0.4

0,3 … 3

0.1

10 … 20

1

8 … 10

0.5

3 … 7

0.2

20 … 50

2.5

10 … 20

1

7 … 10

0.3

50 … 100

5

20 … 50

2.5

10 … 20

0.5

50 … 100

5

20 … 40 1

40 … 100

2.5

Table 1: Minimal error of moisture measurement (absolute)

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5 Mechanical installation

Note: After the mechanical installation, the sensors must be initialized. For this initial calibration (see 7.4) the
measuring volume of the sensor needs to be empty.

Additionally a device or an opening to extract samples from needs to be in close vicinity to the installation
position in order to calibrate the sensor (see 7.5).

5.1 PCE-MWM 210

The sensor assembly is manufactured from galvanized steel and consists of two rings which are used to install the
sensor to the container/mixer. The first ring is a welding flange which needs to be welded to the surface of the
container/mixer. The second ring is used to clamp, mount and align the sensor unit inside the opening of the
container/mixer wall.

Fig. 1 Installation of PCE-MWM 210

1) Gap between sensor and wall of container/mixer which needs to be filled with an adequate sealant

2) Wall of container/mixer

3) Weld connecting the welding flange with the wall of the container/mixer

4) Welding flange (galvanized steel)

5) Clamping ring (galvanized steel)

6) Sensor unit

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5.1.1 Flange

Fig. 2 Welding flange

Fig. 3 Clamping ring

1) Welding flange

2) Threaded bolt

3) Securing nut

4) Clamping ring

5) Clamping screws

6) Adjusting screws

7) Sensor

8) Through-bore

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5.1.2 Installation

1) In order to install the sensor a hole with a diameter of 125 mm needs to be cut out of the wall of the
container/mixer. Afterwards the welding flange (1) is welded centrally over the 125 mm hole. The welding
flange is manufactured from galvanized steel. While cutting and welding, the sensor (7) must not be installed.

2) Screw three threaded bolts (2) into welding flange (1) and fix them with three securing nuts (3).

3) Fasten clamping ring (4) on the sensor (7) by using two clamping screws (5).

4) Position the assembly consisting of sensor and clamping ring on the welding flange by pushing the threaded
bolts through the through-bores (8).

5) Align the sensor by using the adjusting screws (6). The surface of the sensor must be in line with the inner
wall of the container/mixer.

6) Secure the assembly by screwing three securing nuts (3) on the threaded bolts.

7) After tightening all screws and nuts, check the alignment of the sensor on the inside of the wall of the
container/mixer again. In any case the sensor must not protrude inside of the container/mixer. Otherwise the
sensor may be damaged by mixing blades during the mixing process!

Fig. 4 Sensor fixed in ring-assembly

Fig. 5 Ring-assembly

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5.1.3 Sensor Coverage

A sufficient material coverage is required to receive an accurate measurement of the material moisture. The
measuring volume of the sensor is approximately Ø108 mm x 100 mm. A sufficient material coverage should always
be ensured even in case of minimal material level or flow inside the container or on a conveyor belt. Apart from
sufficient material coverage it is also important to avoid metallic components within the measuring field of the sensor.
The minimum distance to metallic components to the side is 50 mm. All of the above factors have to be taken into
account when choosing the installation position of the sensor.

Fig. 6 Distance of PCE-MWM 210 to metallic components

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5.2 PCE-MWM 240A

There are several possibilities of installing the PCE-MWM 240A moisture sensor to a container. The sensor can be
connected to the container wall with welds or screws. The following figures show installation examples since several
different installation setups are possible depending on container dimensions and geometry. The following examples
display a vertical orientation of the sensor. Depending on the application it is also possible to choose a horizontal
orientation as well as any other angle.

5.2.1 Dimensions of the base plate of the sensor

Fig. 7 Dimensions of the base plate of the moisture sensor PCE-MWM 240A

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5.2.2 Installation with welds

Fig. 8 Dimensions of the rectangular cut-out

Fig. 9 Installation with welds

In order to install the base plate of the sensor, a
rectangular cut-out with dimensions of at least 315 x
80 mm needs to be cut from of the container. On
curved surfaces the cut-out dimensions deviate and
need to be calculated individually depending on the
container.

The cutting edges should be smoothed to prevent
material adhering to the inside after installation of the
sensor and to prevent injuries caused by sharp edges.

Note: Please pay attention to the safety instructions
regarding the use of the appropriate cutting tools. Only
persons with appropriate training may carry out the
task.

After the sensor is positioned in the rectangular cut-out, the base plate
can be welded from the outside to the container wall.

Warning: It is prohibited to weld the base plate to the container wall
while the electronic unit is connected to the power supply.

Note: Please pay attention to the safety instructions regarding the use of
the appropriate welding tools. Only persons with appropriate training
may carry out the task.

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5.2.3 Installation with screws

Fig. 10 Dimensions of the rectangular cut-out

Fig. 11 Installation with screws

In order to install the base plate of the sensor, a
rectangular cut-out with dimensions of at least 315 x
80 mm needs to be cut from the container.
Furthermore four holes for the screws have to be
drilled through the container wall with distances of 336
/ 100 mm between. On curved surfaces the cut-out
dimensions deviate and need to be calculated
individually depending on the container.

The cutting edges should be smoothed to prevent
material adhering to the inside after installation of the
sensor and to prevent injuries caused by sharp edges.

Note: Please pay attention to the safety instructions
regarding the use of the appropriate cutting tools.
Only persons with appropriate training may carry out
the task.

After the sensor is positioned in the rectangular cut-out, the base
plate can be screwed from the outside to the container wall.

Warning: It is prohibited to screw the sensor to the container wall
while the electronic unit is connected to the power supply.

Depending on the surface and geometry of the container wall it is
possible that the connection exhibits gaps. In that case especially
fine-grained materials can trickle through the small gaps between
the base plate of the sensor and the container wall. An adequate
sealant should be used to close these gaps.

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5.2.4 Installation with flange

Fig. 12 Dimensions of the rectangular cut-out

Fig. 13 Dimensions of the flange for installation of the moisture sensor PCE-MWM 240A

1) Rectangular cut-out in container wall with
dimensions of at least 360 x 125 mm. Smooth
the edges of the cut-out.

2) Align flange with dimensions as shown in Fig.
13 over the cut-out and weld it to the container
wall from the outside.

3) Screw the sensor with the base plate from the
inside of the container to the flange.

The dimensions of the flange are an example and
exact dimensions may change depending on the
container. Different dimensions or shape of the flange
does not affect the measuring accuracy of the sensor.

Note: Please pay attention to the safety instructions
regarding the use of the appropriate tools. Only
persons with appropriate training may carry out the
task.

Installation with a flange offers two advantages:

1) For maintenance purposes it is easier to remove the
sensor since it is held with screws and is not welded to the
container wall.

2) The base plate of the sensor can be mounted on the same
level as the inside of the container wall. This can help to
reduce material adhesion at the cutting edges and to
improve material flow inside the container.

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5.2.5 Installation on curved surfaces

Fig. 14 Installation on a curved surface

On curved surfaces the rectangular cut-out in the container
wall needs to be individually adjusted to the curvature.
Considering the size of the base plate of 356 x 120 mm a
possible way is to adjust the cut-out in such a way so that
one side is shorter and one side longer than the according
length of the base plate. In this case one edge of the base

plate would “fall” into the container while the other edge

would rest on the cutting edges of the container wall. It is
also possible to individually adjust the geometry of the flange
to a container in order to install the sensor.

Gaps between the container wall and the sensor / flange
should be sealed with a suitable sealant.

Fig. 14 shows the top view of an installation example.

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5.2.6 Sensor coverage

A sufficient material coverage is required to receive an accurate measurement of the material moisture. The
measuring volume of the sensor is approximately 360 x 130 x 100 mm. A sufficient material coverage should always
be ensured even in case of minimal material level or flow inside the container or on a conveyor belt. Apart from
sufficient material coverage it is also important to avoid metallic components within the measuring field of the sensor.
All of the above factors have to be taken into account when choosing the installation position of the sensor.

Fig. 15 Sufficient material coverage of the moisture sensor PCE-MWM 240A

Fig. 16 Insufficient material coverage of the moisture sensor PCE-MWM 240A

Sufficient sensor coverage

Insufficient sensor coverage

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5.3 PCE-MWM 240B

Two welding flanges are used to install the sensor at the measuring location. Therefore the sensor must be
disassembled previous to installation. In order to dismantle the sensor assembly sleeve 3, sleeve 4, welding flange 1
and welding flange 2 must be released and removed from the sensor rod. Sleeve 1 and sleeve 2 can remain on the
rod.

Fig. 17 Components of the moisture sensor PCE-MWM 240B

Fig. 18 Dimensions of the welding flanges

Fig. 18 shows the exact dimensions of the welding flanges. Accordingly the round cut-out for welding flange 1 must be
smaller than 60 mm but not smaller than 52 mm. The round cut-out for welding flange 2 must be smaller than 60 mm
but not smaller than 45 mm.

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Warning: It is not permitted to weld the flanges to the pipe or container while the flanges are connected to the sensor
rod or sleeves. It is also not permitted to install the sensor while the electronic unit is connected to the power supply.
The pipe or container needs to be empty during cutting and welding.

Note: Please pay attention to the safety instructions regarding the use of the appropriate cutting / welding tools. Only
persons with appropriate training may carry out the task.

Fig. 19 Installation of the moisture sensor PCE-MWM 240B

1) After welding the flanges to the pipe/container the sensor can be installed. The sensor rod is inserted from the
left through welding flange 1 and welding flange 2 until sleeve 2 reaches the end position inside welding
flange 1.

2) Sleeve 3 is screwed to the end position inside welding flange 2.

3) The already detached cable which contains the temperature sensor needs to be inserted into the sensor rod
and secured with a temperature-resistant adhesive.

4) Sleeve 1 and sleeve 4 are screwed on the sensor assembly.

5) Gaps between the container wall and the welding flanges should be sealed with a suitable sealant.

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5.3.1 Sensor coverage

A sufficient material coverage is required to receive an accurate measurement of the material moisture. Sufficient
material coverage should always be ensured even in case of minimal material level or flow inside the container or on a
conveyor belt. Apart from sufficient material coverage it is also important to avoid metallic components within the
measuring field of the sensor. All of the above factors have to be taken into account when the installation position of
the sensor is chosen.

Fig. 20 Sufficient material coverage of the moisture sensor PCE-MWM 240B

Fig. 21 Insufficient material coverage of the moisture sensor PCE-MWM 240B

Insufficient sensor coverage

Sufficient sensor coverage

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6 Electrical installation

Always use shielded cables to connect the electronic unit of the moisture sensors to external devices, displays and the
power supply.

6.1 Cabling

PCE Instruments recommends a sensor / actuator cable type M12 (e.g. Lapp Group).

6.1.1 General properties

Coding

A

Protection

IP65 / IP67 / IP68

Insulation resistance

≥ 100 MΩ

Volume resistance

≤ 5 mΩ

Overvoltage category

II

6.1.2 Power supply

The connector for the power supply needs to be a sensor / actuator cable, 4-pos., PUR black, straight socket M12 on
free conductor end (e.g.: Lapp Group art. no. 22260322).

6.1.2.1 Technical data

Number of contacts

4

Core identification code

brown (1), white (2), blue (3), black (4)

Core insulation, material

PP

Outer sheath

PUR

Outer diameter, cable

4.1 mm

Conductor, cross-sectional area

0.34 mm²

Ambient temperature, fixed installation

-40 °C … +80 °C

Ambient temperature, flexing

-25 °C … +80 °C

Minimum bending radius, fixed installation

5 x cable diameter

Minimum bending radius, flexing

10 x cable diameter

Nominal voltage

≤ 300 V

Rated current

4 A

Test voltage

≥ 3000 V

Standard / approvals

IEC 61076-2-101, E249137

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6.1.2.2 Technical drawings

Fig. 22 M12 connector

Fig. 23 Wiring diagram

Fig. 24 Pin assignment

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Fig. 25 Core identification code

brown (1), white (2), blue (3), black (4)

Fig. 26 Pin assignment for power supply

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6.1.3 Communication

The connector for the communication interface needs to be a sensor / actuator cable, 5-pos., PUR black, straight
socket M12 on free conductor end (e.g.: Lapp Group art. no. 22260404).

6.1.3.1 Technical data

Number of contacts

5

Core identification code

brown (1), white (2), blue (3), black (4), green­yellow (5)

Core insulation, material

PP

Outer sheath

PUR

Outer diameter, cable

4.5 mm

Conductor, cross-sectional area

0.34 mm²

Ambient temperature, fixed installation

-40 °C … +80 °C

Ambient temperature, flexing

-25 °C … +80 °C

Minimum bending radius, fixed installation

5 x cable diameter

Minimum bending radius, flexing

10 x cable diameter

Nominal voltage

≤ 300 V

Rated current

4 A

Test voltage

≥ 3000 V

Standard/ approvals

IEC 61076-2-101, E249137

6.1.3.2 Technical drawings

Fig. 27 M12 connector

Fig. 28 Wiring diagram

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Fig. 29 Pin assignment

Fig. 30 Core identification code

brown (1), white (2), blue (3), black (4), green­yellow (5)

Fig. 31 Pin assignment for signal output

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6.2 Analog output

The moisture measurement of the moisture sensors PCE-MWM 2xx can be forwarded with a 4 … 20 mA current loop
to external devices like e.g. PLC or display. The default scaling of the analog output is as followed:

 4 mA  0 % Moisture content
 20 mA  100 % Moisture content

This scaling can be adjusted with the program PCE-MWM Manager depending on the application.

6.2.1 Connection

 +4 … 20 mA  Left sensor / actuator plug pos. 1 (brown)
 -4 … 20 mA  Left sensor / actuator plug pos. 4 (black)

Fig. 32 Pin assignment for analog output

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6.3 RS-485 interface

Another way to communicate with the moisture sensors PCE-MWM 2xx is the serial port RS-485. This port provides
the Modbus RTU protocol. There are several registers which can be read in order to receive data regarding moisture
content and temperature among other parameters.

6.3.1 Connection

 Modbus RTU A(+)  Left sensor / actuator plug pos. 2 (white)
 Modbus RTU B(-)  Left sensor / actuator plug pos. 3 (blue)
 RS-485 shield  Left sensor / actuator plug pos. 5 (green-yellow)

Fig. 33 Pin assignment for serial port RS-485

6.3.2 Protocol

 Reading of the registers is carried out with the command 03 (03h), recording - command 16 (10h)
 A command for testing echo returns is supported 08 (08h).
 Simultaneous recording (writing) or reading of not more than 48 registers is allowed for one query.

Supported Baud rates

300, 600, 1200, 2400, 4800, 9600, 14400, 19200,
38400, 56000, 57600, 115200

Parity

None

Number of stop bits

2

Register types

16 bit unsigned integer

6.3.2.1 Write protection

Before attempting to write registers the write protection needs to be disabled by writing the number 4988 (137Ch) into
the register 0020 (0014h). Additionally some registers are read-only and will not accept write commands. When
attempting to write into read-only registers or when the write protection was not disabled, the moisture meter does not
reply.

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6.3.2.2 Default settings of the electronic unit

Baud rate

19200

Parity

None

Stop bits

2

Address

127

6.3.2.3 Description of registers

Register
address
(DEC)

Register
address
(HEX)

Description

R/W
0000

0000

Measured moisture in hundredths of a percent

R

0001

0001

Temperature in Kelvin

R

0002

0002

Error code. (If 0, there are no errors)

R

0020

0014

Code of write protection

R/W

0163

00A3

Total number of calibration tables

R

0164

00A4

The number of the current calibration table (starting with 1)

R/W

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7 PCE-MWM Manager

7.1 Introduction

The measuring principle of the PCE-MWM 2xx moisture sensors utilizes the dielectric properties of material to
determine their moisture. These dielectric properties change with moisture content which allows the sensor to
measure the moisture. Different materials exhibit varying changes of their dielectric properties when the material
moisture increases or decreases. Consequently a specific calibration is only valid for a single material and different
materials need to be calibrated separately.

The program PCE-MWM Manager is used to create a calibration. It displays the dimensionless sensor data in a chart.
The sensor data correlates with the moisture of the tested material (see Fig. 34) which shows the moisture content
against the sensor data. Accordingly the calibration curves differ for various materials meaning the identical sensor
value equals different moisture content depending on the material. The objective of the calibration is to create these
characteristic curves for each material.

Fig. 34 Calibration curves for different material

Material 1

Material 4

Material 3

Material 2

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7.2 Overview PCE-MWM Manager

The program PCE-MWM Manger is used to connect the electronic unit to a PC in order to change the settings and to
create a material-specific calibration.

Fig. 35 PCE-MWM Manager main window

Description:

1) Navigation: Main navigation for connection, calibration and settings

2) Tree view: Display and selection of created calibrations

3) Chart: Display of measuring points and calibration curve of selected calibration

4) Test: Display of measurements when using the function Test

5) Status bar: General information and current parameters

1 Navigation

2 Tree view

3 Chart

4 Test

5 Status bar

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30

7.3 Connection electronic unit

After attaching the electronic unit to a PC using an RS-485 converter, a connection can be established with PCE­MWM Manager. An RS-485/USB converter is included in the shipment but other RS-485/USB converter can also be
used. When using the included converter it should be ensured that the RS-485 function of the converter (see
Fig. 36) was automatically activated:

1) Open device manager

2) Extend Ports (Com & LPT)

3) Right-click on RS-485 converter

4) Select tab Port Settings

5) Check if checkbox RS-485 is ticked and accept with OK

Fig. 36 Configuring RS-485 converter

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After making sure that the RS-485 function of the converter is activated, a connection to the electronic unit can be
established:

1) Open settings with the button of the main navigation bar

2) Select correct COM-Port in the menu (see Fig. 37)

3) Select default parameters of the electronic unit: Baud rate 19200, address 127

4) Apply settings with

5) Establish connection with the button in the main navigation bar over the label Connection

Fig. 37 Settings

A successful connection is indicated in the bottom status bar with the message connected (see Fig. 38).

Fig. 38 Successful connection

After successfully connecting to the electronic unit, the initial calibration must be performed. The initial calibration
needs to be carried out only once after the mechanical installation. The material calibration can be started after
finishing the initial calibration. If the sensor is pre-calibrated then material calibration is not necessary and moisture
measurement can begin immediately.

7.4 Initial calibration

Before the material calibration or moisture measurement in case of a pre-calibrated sensor can begin, an initial
calibration must be performed. For this reason the buttons for the calibration are not active when starting PCE-MWM
Manager for the first time and a corresponding message is displayed in the status bar (see Fig. 39).

Fig. 39 Message about missing initial calibration

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Warning: The measuring volume of the sensor must be empty while carrying out the initial calibration.
After making sure that the measuring volume of the sensor is empty, the initial calibration can be started:

1) Establish connection to the electronic unit (see 7.3).

2) Open menu Configuration electronic unit (see Fig. 40) with the button of the main navigation bar

3) Start initial calibration with the button

Fig. 40 Configuration electronic unit

Starting the initial calibration displays the following dialog box (see Fig. 41):

Fig. 41 Dialog for initial calibration

In case the initial calibration has not been carried out after mechanical installation the dialog must be confirmed with

Yes which immediately performs the initial calibration. After successfully finishing the initial calibration, the message
Initial calibration OK is displayed in the status bar (see Fig. 42) and material calibration can be started.

Note: The initial calibration must be carried out only a single time after mechanical installation and is used as a
reference for subsequent material calibration. It is not required to repeat this procedure when calibrating the sensor to
a new material.

Fig. 42 Initial calibration successful

Performing the initial calibration creates a local entry on the PC which was used to carry out the initial calibration. If
PCE-MWM Manager is started on another PC to create or resume a calibration, the status bar will indicate that an
initial calibration is required. This is caused by the missing entry on the new PC and the buttons for the calibration are
not active.

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In this case the dialog for the initial calibration needs to be started and subsequently No must be selected. This
correctly skips the initial calibration and creates a local entry on the PC regarding the already carried out initial
calibration which activates the buttons for the calibration.

Note: If the sensor is moved to another position, a new initial calibration is required at the new position.

7.5 Calibration

After finishing the initial calibration, the buttons for the calibration are active. Generated or imported calibrations are
displayed in the tree view (see Fig. 43) on the left side of the main window.

Create new calibration
Edit calibration
Delete calibration

Fig. 43 Tree view of calibrations

The tree view shows the names of the calibrations and corresponding tables for different temperatures. Calibrations
can be created, edited and deleted with the respective buttons of the main navigation.

7.5.1 Create new calibration

The button in the main navigation bar creates a new calibration. A name for the calibration needs to be entered in
the new window (see Fig. 44) and up to 4 calibration tables can be added. Each calibration table is used to calibrate
the sensor to a single material at a specific temperature.

New calibration table
Edit calibration table
Delete calibration table

Fig. 44 Window for new calibration

Since the dielectric properties of a material change to a varying degree with the temperature, a calibration is usually
only valid for a certain temperature range. If the material temperature varies greatly at the measuring position, it is
possible to use multiple calibration tables to compensate the calibration for changes in material temperature. In case
the material temperature does not change significantly, a single calibration table is sufficient and the remaining 3
tables can be left empty. A combination of 2, 3 or 4 calibration tables are also possible.

7.5.2 Calibration table

The button in the window for a new calibration opens a new calibration table (see Fig. 45) which is used to
calibrate a material at a specific temperature.

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Fig. 45 Calibration table

Record sensor data
Enter moisture of material
Delete sensor data

After ensuring a sufficient coverage of the sensor with material, the current sensor data can be recorded with the
button which adds a new entry in the table (see Fig. 47). At the same time the integrated temperature sensor

measures the material temperature which is added in the input box at the top of the window.
Depending on the material a calibration table is usually only valid for a certain temperature range. For this reason it is

important to only add measuring data to the table which does not differ greatly in temperature.
Note: The following warning is displayed (see Fig. 46) if the temperature of newly recorded data exceeds the

temperature which is shown in the box at the top of the window. This may lead to reduced accuracy when operating
the sensor with this calibration. In any case the calibration can still be continued.

Fig. 46 Warning if measured temperature of recorded date exceeds threshold

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The displayed sensor data is created by averaging multiple individual measurements of the sensor. By default 10
individual measurements are averaged and the amount can be changed in the settings if necessary (see 7.11).

Fig. 47 Calibration table with first entry

The recorded sensor data is displayed in the table and the corresponding material moisture needs to be assigned. In
order to assign the moisture a sample of the material needs to be gathered. The sample should be extracted as soon
as possible after recording the sensor data and should be collected as close as possible from the installation position
of the sensor. This procedure requires careful handling since it directly affects the quality of the calibration (see 8.1).

After the moisture content of the sample has been determined (see 8.2), it can be matched to the recorded data.
Assigning the moisture can be accomplished with the button or a double click on the entry in the table (see Fig.

48).

Fig. 48 Assign moisture to sensor data

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36

This procedure needs to be repeated several times to generate enough data for the calibration (see Fig. 49). It is also
possible to record multiple sensor measurements in one session and extract their respective samples for the purpose
of analyzing multiple samples in parallel. Afterwards the moisture contents can be assigned to the respective sensor
data. In that case correct labeling is required in order to ensure correct assignment of the moisture to the sensor data.

Fig. 49 Calibration table with multiple measurements

At minimum 3 measurements have to be completed in order to transfer the calibration to the electronic unit. Ideally
multiple complete measurements cover the expected range of the material moisture.

A low amount of measurements, which barely differ in material moisture, could lead to high extrapolated errors when
the current material moisture greatly differs from the measurements which were used to generate the calibration.
Depending on the situation it may not be possible to complete enough measurements covering the whole expected
range of material moisture in a short amount of time. In this case it is recommended to begin a calibration and add
more measurements over a longer period for higher accuracy and validation.

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7.5.3 Evaluate calibration

The completed measurements are displayed in a diagram in the right half of the window for the calibration table. A
best-fit line is also displayed after at least 3 moisture contents were assigned to the respective sensor data. Since
most materials exhibit a linear dependence between sensor data and moisture content, the best-fit line equals the
calibration.

The best-fit line is used by the electronic unit to determine the moisture content which is sent to the output interface.
Since the best-fit line represents a linear interpolation, small deviations between measurement data and best-fit line
result in a calibration with high accuracy. This is illustrated with the following 3 examples:

Fig. 50 shows a calibration with high accuracy. In this
case the measurement data coincide with the best-fit line
in a nearly ideal way which results in little errors.
Furthermore the measurement data sufficiently covers the
expected range of material moisture.

When creating a new calibration high errors may occur if
only a few measurements are recorded. This is further
compounded if the material moisture is expected to vary a
high amount but only a small range was covered with
recorded data. Adding more measurement data to the
calibration can help reduce this error.

Fig. 50 Calibration with high accuracy

Fig. 51 shows a calibration with reduced accuracy. In
general a linear dependence between sensor data and
moisture can still be identified like in the previous
example.

In comparison to Fig. 50 higher deviations exist between
the measurement data and the best-fit line. This would
result in errors of several percent of absolute moisture
measurement when using this calibration to determine the
moisture content with the sensor.

In this case outliers should be reviewed with regard to
correct acquisition of sensor data or respective moisture
content.

Depending on the desired accuracy the expected errors of
this calibration can be acceptable and the calibration can
still be expanded with more measurement data at any
time.

Fig. 51 Calibration with reduced accuracy

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Fig. 52 shows a flawed calibration. The measurement
data does not exhibit a linear dependence between
sensor data and moisture content. The data also spreads
heavily around the best-fit line which means that this
calibration is not suited to determine the moisture content.

In this case the installation position of the sensor needs to
be reviewed in terms of sufficient material coverage at all
times. Incorrect extraction or handling of the gathered
samples could also lead to these errors. It should also be
checked if the moisture contents of the extracted samples
were assigned to the correct sensor data in the calibration
table.

Fig. 52 Flawed calibration

7.5.4 Finish calibration

After recording at least 3 sensor data and subsequent assignment of corresponding moisture content, the calibration
can be finalized by applying the entries with the button in order to access the buttons of the main navigation. The

created calibrations need to be transferred to the electronic unit which calculates the moisture content from the sensor
data and generates the signal for the serial interface and analog output.

7.6 Transfer calibration to / from electronic unit

Up to 20 calibrations can be saved on the electronic unit. This storage is independent of the calibrations in the
program PCE-MWM Manager which means that the calibrations have to be transferred with these dedicated functions.

 Transfer calibration to electronic unit

This function transfers a calibration from PCE-MWM Manager to the electronic unit.

Add slot for calibration
Delete all calibrations

Fig. 53 Transfer calibration to electronic unit

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At first a calibration needs to be selected in the tree view of PCE-MWM Manager. After starting the transfer with the
button the selected calibration is displayed in the title of the window (see Fig. 53) and an internal slot in the
electronic unit needs to be selected. Upon confirmation with the button the calibration will be transferred to the

electronic unit.

Up to 20 calibrations can be saved and the current amount of slots can be increased with the button . It is also
possible to overwrite an already existing calibration in a slot with a new calibration.

Warning: It is not possible to delete a single calibration. The button deletes every calibration at the same time!
When transferring the calibration only the best-fit line is transferred and the measured data to create the best-fit line

are not stored in the electronic unit. For the purpose of resuming and adding to a calibration it needs to be saved in a
.csv-file (see 7.7).

 Transfer calibration from electronic unit

This function is used to transfer a calibration from the electronic unit to the program PCE-MWM Manager. This
function is used for diagnostics and backup and is not suitable to resume a calibration since only the best-fit line is
stored in the electronic unit.

Fig. 54 Transfer best-fit line from electronic unit

The button starts the dialog for transferring a calibration from the electronic unit. After selecting the internal slot,
entering a name and confirming with the button , the calibration is loaded into the program PCE-MWM Manager

(see Fig. 55). As mentioned above only the best-fit line is transferred which always includes 15 measured values.

Fig. 55 Imported best-fit line from electronic unit displayed in the tree view

Furthermore the calibration always includes 4 calibration tables when transferred from the electronic unit. If the
originally transferred calibration only included 1 calibration table, the remaining 3 tables are a copy of the first table.
The equivalent is also true when the originally transferred calibration included 2 or 3 calibration tables, which means
that the remaining calibration tables are a copy of the first table.

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7.7 Export / import calibration in .csv-file

The calibration can be suspended at any time and resumed at a later time. For this purpose a calibration needs to be
selected in the tree view which can then be exported and imported using a .csv-file. PCE-MWM Manager does

not automatically save changes to calibrations and a note is displayed when trying to close the program and unsaved
calibrations are detected.

7.8 Select calibration in electronic unit

The calibration is used to calculate the moisture content from the sensor data. Up to 20 calibrations can be saved in
the electronic unit, but only one calibration can be active at any time. Since calibrations are only valid for a specific
material this function is required to switch between calibrations, which are stored in the electronic unit, when the

measured material changes. The calibration can be switched with the button of the main navigation and after
confirming the dialog the currently active calibration number is displayed in the status bar (see Fig. 56). It is also
possible to change the calibration with the corresponding register if the electronic unit is integrated into an already
existing RS-485 network.

Fig. 56 Currently selected calibration in the electronic unit

7.9 Establish / close connection

After changing the connection settings (see 7.3), a connection can be directly established or closed with these buttons
of the main navigation bar.

7.10 Test

This button activates the test function in the bottom bar (see Fig. 57). This display is refreshed every 2 seconds and
shows the current sensor data, calculated moisture content and temperature. The moisture content is calculated with
the currently selected calibration in the electronic unit (see 7.8).

Fig. 57 Status bar for Test

7.11 Settings

The settings menu of the program PCE-MWM Manger (see Fig. 37) can be opened with the main navigation bar.

 Connection

In order to establish a connection to the electronic unit, the parameters COM-port, baud rate and address need to be
adjusted (see 7.3). The parameters can be changed with these settings. The default parameters are: Baud rate
19200, address 127.

 Calibration

This setting changes how many individual measurements are averaged in order to generate an entry for the sensor
data in the calibration table (see 7.5.2).

 Date format

The format of date and time can be changed with this setting.

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7.12 Configuration electronic unit

After successfully establishing a connection between the electronic unit and a PC, the menu Configuration electronic
unit can be opened with the main navigation bar (see Fig. 40). The settings in this menu are directly stored in the

electronic unit after applying changes with the button .

 Moving average

This setting is used to adjust a moving average of the measure moisture content for the serial interface or analog
output. By default this setting is set to 1 which means that every second the currently measure moisture content is
forwarded to the output interface. This setting can be set from 1 … 127 and the moving average is calculated
accordingly. Depending on the application this option can help smooth the output signal.

 Analog output

The moisture measurement of the moisture sensors PCE-MWM 2xx can be forwarded with a 4 … 20 mA signal to
external devices like e.g. PLC or display. By default 4 mA and 20 mA equal 0% and 100% moisture content
respectively. This scaling can be changed with these parameters.

 RS-485 interface

In order to integrate the electronic unit into an already existing RS-485 network, the baud rate or address of the
electronic unit may need to be changed. This can be achieved by changing the settings in the RS-485 interface box
which immediately changes the parameters of the electronic unit upon confirmation.

 Initial calibration

After the mechanical installation of the sensor, an initial calibration (see 7.4) must be carried out. The initial calibration
can be started with this button.

7.13 Language

The language of the program PCE-MWM Manager can be changed with this menu. The currently supported
languages include English and German.

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8 Appendix

8.1 Notes for gathering and handling of samples

The following notes should be considered in order to create a calibration with high accuracy:

 The sample should be extracted immediately after recording sensor data
 The sample should be extracted as close as possible from the installation position of the sensor in order to

receive a representative result

 An airtight container must be used to collect and store the sample
 The collected sample should not be exposed to heat or direct sunlight before determining the moisture content

8.2 Determining moisture content of samples

The calibration of a material requires assignment of the actual moisture to the corresponding sensor data. For most
materials the Loss on Drying (LOD) method is sufficient to provide the actual moisture of a sample. With this method a
sample is dried in an oven and the difference of start and end weight enables the calculation of the water content. This
process can be performed manually with a drying oven or in an automated way with moisture analyzers.

8.2.1 Drying oven

Required equipment:

 Drying oven
 Oven-safe containers
 Scale (Example: PCE-BSH 10000)

Before the sample is placed in the container, the container must be weighed. Then the sample can be placed in the
oven-safe container. Depending on the accuracy of the scale, the weight of the sample must be above a certain
threshold. Otherwise a too small sample would lead to inaccurate values when calculating the moisture content.
Afterwards the container can be placed in the oven to dry the sample. The sample needs to be dried while being
weighed periodically until the weight does not decrease anymore which means that all the water has evaporated. The
water content 



of the sample can be calculated with the following formula:





󰇟󰇠 

 



 



 

with

 



 

 



 

 



   

The above formula calculates the moisture content of a sample against the mass before drying, i.e. wet sample. Some
industries define the moisture content against the dry mass which can be calculated with the following formula:





󰇟󰇠 

 



 



 

A collected sample should be divided into several smaller samples which are then analyzed to determine their
moisture content. Afterwards the average of the individual samples should be assigned to the respective sensor data
in the calibration table.

The overall drying time mostly depends on the material, drying temperature and sample weight. Industry standards
should be checked to set the correct drying temperature since an unsuitable drying temperature could lead to wrong
results. This is caused by the evaporation of other volatile components when the drying temperature is set too high.
Also the sample should not be too small since a bigger sample leads to more accurate results depending on the scale.

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Example:
Total mass of collected sample: 10 kg

Sample [g]

Container  [g]

Dried sample  [g]

Moisture content





[%] (wet)

Moisture content





[%] (dry)

2000

500

1700

20.00

25.00

2000

500

1705

19.67

24.48

2000

500

1695

20.33

25.52

Average:

20.00

25.00

If the moisture contents of the individual samples deviate by several percent, an inhomogeneous moisture distribution
could be the cause. Another issue could be the extraction and storage of the samples or an insufficiently small
sample. This may lead to reduced accuracy of the calibration.

8.2.2 Moisture analyzer

Moisture analyzers (Example: PCE-MA Series) determine the moisture in an automated manner. A sample is dried
with integrated halogen lamps and automatically weighed before and after drying in order to calculate the moisture
content. In comparison to the drying oven, moisture analyzers process a smaller sample. This is compensated by a
precise scale which enables an accurate result. Another advantage is the much shorter drying time because of the
smaller sample mass. For this reason the moisture content of a sample can be determined in an efficient way and with
substantially less effort compared to the manual method described in the chapter before.

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9 Contact

If you have any questions about our range of products or measuring instruments please contact PCE Instruments.

Germany France Spain

PCE Deutschland GmbH PCE Instruments France EURL PCE Ibérica S.L.
Im Langel 4 76, Rue de la Plaine des Bouchers Calle Mayor, 53
D-59872 Meschede 67100 Strasbourg 02500 Tobarra (Albacete)
Deutschland France España
Tel.: [phone] Téléphone: [phone] Tel. : [phone]
Fax: [phone] Numéro de fax: [phone] Fax: [phone]
[e-mail] [e-mail] [e-mail]
www.pce-instruments.com/deutsch www.pce-instruments.com/french www.pce-instruments.com/espanol

USA United Kingdom Italy

PCE Americas Inc. PCE Instruments UK Ltd PCE Italia s.r.l.
711 Commerce Way suite 8 Units 12/13 Southpoint Business Park Via Pesciatina 878 / B-Interno 6
Jupiter / Palm Beach Ensign Way, Southampton 55010 LOC. GRAGNANO
33458 FL Hampshire CAPANNORI (LUCCA)
USA United Kingdom, SO31 4RF Italia
Tel: [phone] Tel: [phone] Telefono: [phone]
Fax: [phone] Fax: [phone] Fax: [phone]
[e-mail] [e-mail] [e-mail]
www.pce-instruments.com/us www.pce-instruments.com/english www.pce-instruments.com/italiano

The Netherlands Chile Hong Kong

PCE Brookhuis B.V. PCE Instruments Chile S.A. PCE Instruments HK Ltd.
Institutenweg 15 RUT: 76.154.057-2 Unit J, 21/F., COS Centre
7521 PH Enschede Santos Dumont 738, local 4 56 Tsun Yip Street
Nederland Comuna de Recoleta, Santiago, Chile Kwun Tong
Telefoon: [phone] Tel. : [phone] Kowloon, Hong Kong
Fax: [phone] Fax: [phone] Tel: [phone]
[e-mail] [e-mail] [e-mail]

www.pce-instruments.com/dutch www.pce-instruments.com/chile www.pce-instruments.cn

China Turkey

Pingce (Shenzhen) Technology Ltd. PCE Teknik Cihazları Ltd.Şti.
West 5H1,5th Floor,1st Building Halkalı Merkez Mah.
Shenhua Industrial Park, Pehlivan Sok. No.6/C
Meihua Road,Futian District 34303 Küçükçekmece - İstanbul
Shenzhen City Türkiye
China Tel: [phone]
Tel: [phone] Faks: 0212 705 53 93
[e-mail] [e-mail]
www.pce-instruments.cn www.pce-instruments.com/turkish