Vaisala HUMICAP MMT162 User manual

USER'S GUIDE
Vaisala HUMICAP
®
Moisture and
Temperature Transmitter for Oil
MMT162
M210934EN-B

PUBLISHED BY
Vaisala Oyj Phone (int.): [phone]
P.O. Box 26 Fax: [phone]
FI-00421 Helsinki
Finland
Visit our Internet pages at http://www.vaisala.com/
© Vaisala 2009
No part of this manual may be reproduced in any form or by any means, electronic or
mechanical (including photocopying), nor may its contents be communicated to a third
party without prior written permission of the copyright holder.
The contents are subject to change without prior notice.
Please observe that this manual does not create any legally binding obligations for
Vaisala towards the customer or end user. All legally binding commitments and
agreements are included exclusively in the applicable supply contract or Conditions of
Sale.

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Table of Contents
CHAPTER 1
GENERAL INFORMATION............................................................................5
About This Manual...................................................................5
Contents of This Manual.......................................................5
Version Information...............................................................6
Related Manuals...................................................................6
General Safety Considerations.............................................6
Feedback...............................................................................6
Product Related Safety Precautions......................................7
Recycling ..................................................................................7
Regulatory Compliances.........................................................7
Electromagnetic Compatibility...............................................7
Trademarks...............................................................................8
License Agreement..................................................................8
Warranty....................................................................................8
CHAPTER 2
PRODUCT OVERVIEW..................................................................................9
Introduction to MMT162...........................................................9
Basic Features and Options..................................................10
Transmitter Structure.............................................................10
Typical Applications ..............................................................12
Method Used for Measuring Moisture in Oil........................12
Lubrication Oil .....................................................................12
Transformer Oil...................................................................13
CHAPTER 3
INSTALLATION............................................................................................15
Installing the Transmitter ......................................................15
Wiring ......................................................................................17
Connection Cables..............................................................18
Power Supply Requirements...............................................20
CHAPTER 4
OPERATION.................................................................................................21
Getting Started .......................................................................21
Analog Output Operation Modes..........................................21
Normal Operation Mode and Malfunction Alarm.................22
Limit Alarm ..........................................................................22
Serial Communication ...........................................................23
Connecting to Serial Interface.............................................23
Installing the Driver for the USB Cable ...............................24
Terminal Program Settings .................................................25

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List of Serial Commands .......................................................27
Device Information and Status..............................................28
Show Device Information ....................................................28
Show Firmware Version ......................................................28
Configuring Serial Line Operation........................................29
Set Serial Line Settings.......................................................29
Set Serial Line Response Time...........................................30
Set Transmitter Address......................................................30
Format Measurement Output..............................................30
Select Unit...........................................................................32
Set Serial Interface Mode....................................................32
Configuring Measurement Parameters ................................32
Select Analog Output Quantity and Scaling........................32
Set Analog Output Mode (mA/V).........................................33
Calibrate Analog Output......................................................34
Set Malfunction Alarm Output for Analog Channels............34
Set Alarm Limits for Analog Outputs / LED Indication.........35
Set Voltage for LED Alarm..................................................35
Extend Analog Output Range..............................................36
Serial Line Output Commands..............................................36
Start Measurement Output..................................................36
Stop Measurement Output..................................................36
Set Output Interval...............................................................37
Output Reading Once..........................................................37
Troubleshooting Commands.................................................38
Display the Currently Active Errors .....................................38
Test Analog Outputs............................................................38
Other Commands ...................................................................39
Opening the Transmitter in POLL Mode .............................39
Closing the Connection to a Transmitter in POLL Mode.....39
Display Command List ........................................................40
Reset Transmitter................................................................41
Restore Factory Settings.....................................................41
ppm Conversion .....................................................................41
MMT162 ppm Conversion for Transformer Oils..................41
Conversion Model with Average Coefficients......................42
Conversion Model with Oil-specific Coefficients .................42
Setting Oil Coefficients Using Serial Line............................43
OIL..................................................................................43
Determination of Oil-Specific Coefficients...........................43
CHAPTER 5
MAINTENANCE............................................................................................47
Cleaning...................................................................................47
Changing the Probe Filter......................................................48
Changing the Sensor .............................................................48
Error States.............................................................................48
Technical Support ..................................................................49
Return Instructions ................................................................49
Vaisala Service Centers.........................................................50
CHAPTER 6
CALIBRATION AND ADJUSTMENT...........................................................51

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MM70 in Checking and Adjusting.........................................52
One-Point Relative Humidity Adjustment............................52
Using Serial Line.................................................................52
CRH ...............................................................................52
Using MI70..........................................................................53
One-Point Temperature Adjustment ....................................56
Using Serial Line.................................................................56
CT ..................................................................................56
Using MI70..........................................................................57
Analog Output Adjustment....................................................58
CHAPTER 7
TECHNICAL DATA......................................................................................59
Measured Values....................................................................59
Operating Environment .........................................................60
Inputs and Outputs ................................................................60
Mechanics...............................................................................60
Spare Parts and Accessories................................................61
Dimensions in mm (inches) ..................................................62
List of Figures
Figure 1 Moisture and Temperature Transmitter for Oil MMT162..........11
Figure 2 The Water Solubility of Transformer Oils versus Temperature14
Figure 3 Removing the Transportation Protection Cap..........................15
Figure 4 Installing the Transmitter..........................................................16
Figure 5 Connecting the Cable...............................................................16
Figure 6 Connectors I and II...................................................................17
Figure 7 Connector Pinout......................................................................17
Figure 8 Cable with Snap-On Connector ...............................................18
Figure 9 Cable with Threaded Connector ..............................................18
Figure 10 Cable with 90° Angle Threaded Connector..............................19
Figure 11 LED Cable................................................................................19
Figure 12 USB Serial Interface Cable ......................................................20
Figure 13 PuTTY Terminal Application ....................................................26
Figure 14 Main Menu................................................................................53
Figure 15 Functions Menu........................................................................53
Figure 16 Metal Housing Transmitter Dimensions...................................62
Figure 17 Plastic Housing Transmitter Dimensions .................................63
List of Tables
Table 1 Manual Revisions.......................................................................6
Table 2 Related Manuals ........................................................................6
Table 3 Quantities Measured and Calculated by MMT162.....................9
Table 4 Default Serial Interface Settings...............................................23
Table 5 Serial Line Commands.............................................................27
Table 6 Modifiers...................................................................................31
Table 7 Analog Output Modes...............................................................33
Table 8 Error Messages........................................................................49

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Chapter 1 ________________________________________________________ General Information
VAISALA________________________________________________________________________ 5
CHAPTER 1
GENERAL INFORMATION
This chapter provides general notes for the manual and the product.
About This Manual
This manual provides information for installing, operating, and
maintaining Vaisala HUMICAP®Moisture and Temperature Transmitter
for Oil MMT162.
Contents of This Manual
This manual consists of the following chapters:
- Chapter 1, General Information, provides general notes for the manual
and the product.
- Chapter 2, Product Overview, introduces the features, advantages, and
the product nomenclature
- Chapter 3, Installation, provides you with information that is intended
to help you install the product.
- Chapter 4, Operation, provides information that is needed in basic
maintenance of the product.
- Chapter 5, Maintenance, provides information that is needed in basic
maintenance of the product.
- Chapter 6, Calibration and Adjustment, provides information that is
needed in calibration and adjustment of the product.
- Chapter 7, Technical data, provides the technical data of the product.

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Version Information
Table 1 Manual Revisions
Manual Code Description
M210934EN-A September 2008 - First version
M210934EN-B March 2009 - Updated cable specification
Related Manuals
Table 2 Related Manuals
Manual Code Manual Name
M210935EN-A Vaisala HUMICAP®Moisture and Temperature
Transmitter for Oil MMT162 Quick Reference Guide
General Safety Considerations
Throughout the manual, important safety considerations are highlighted
as follows:
WARNING Warning alerts you to a serious hazard. If you do not read and follow
instructions very carefully at this point, there is a risk of injury or even
death.
CAUTION Caution warns you of a potential hazard. If you do not read and follow
instructions carefully at this point, the product could be damaged or
important data could be lost.
NOTE Note highlights important information on using the product.
Feedback
Vaisala Customer Documentation Team welcomes your comments and
suggestions on the quality and usefulness of this publication. If you find
errors or have other suggestions for improvement, please indicate the
chapter, section, and page number. You can send comments to us by e-
mail: [email protected]

Chapter 1 ________________________________________________________ General Information
VAISALA________________________________________________________________________ 7
Product Related Safety Precautions
The Vaisala HUMICAP®Moisture and Temperature Transmitter for Oil
MMT162 delivered to you has been tested for safety and approved as
shipped from the factory. Note the following precautions:
WARNING Ground the product, and verify outdoor installation grounding
periodically to minimize shock hazard.
CAUTION Do not modify the unit. Improper modification can damage the product
or lead to malfunction.
Recycling
Recycle all applicable material.
Dispose of batteries and the unit according to statutory regulations. Do
not dispose of with regular household refuse.
Regulatory Compliances
The Vaisala HUMICAP®Moisture and Temperature Transmitter for Oil
MMT162 complies with the following performance and environmental
test standards:
Electromagnetic Compatibility
EN 61326-1:2006-04 + Am1:1998, Electrical equipment for
measurement, control and laboratory use - EMC requirements - Industrial
environment.
CISPR16/22 Class B, EN/IEC 61000-4-2, EN/IEC 61000-4-3, EN/IEC
61000-4-4, EN/IEC 61000-4-5, EN/IEC 61000-4-6

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Trademarks
HUMICAP®is a registered trademark of Vaisala Oyj.
Microsoft®, Windows®, Windows®2000, Windows Server®2003,
Windows®XP, and Windows®Vista are registered trademarks of
Microsoft Corporation in the United States and/or other countries.
License Agreement
All rights to any software are held by Vaisala or third parties. The
customer is allowed to use the software only to the extent that is provided
by the applicable supply contract or Software License Agreement.
Warranty
For certain products Vaisala normally gives a limited one-year warranty.
Please observe that any such warranty may not be valid in case of
damage due to normal wear and tear, exceptional operating conditions,
negligent handling or installation, or unauthorized modifications. Please
see the applicable supply contract or Conditions of Sale for details of the
warranty for each product.

Chapter 2 __________________________________________________________ Product Overview
VAISALA________________________________________________________________________ 9
CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces the features, advantages, and the product
nomenclature of Moisture and Temperature Transmitter for Oil
MMT162.
Introduction to MMT162
The MMT162 transmitter is a microprocessor based instrument for the
measurement of moisture in terms of water activity, for example in the
lubrication of circulation systems or in transformer oil. The probe
incorporates a capacitive thin film sensor. The operation of the sensor is
based on changes in its capacitance as the thin polymer film absorbs
water molecules.
The MMT162 transmitter is available with either metal or plastic
housing. The transmitter can be configured in many ways: two analog
output signals can be scaled, the measurement ranges can be changed
within certain limits and there are two mechanical connection options,
ISO and NPT 1/2. The MMT162 probe is supplied with a three or five
meter connection cable.
The MMT162 also provides for accurate temperature measurement. It is
an easy-to-install on-line probe which can be calibrated against, for
example, traceable salt solutions.
Table 3 Quantities Measured and Calculated by MMT162
Quantity Abbreviation Metric Unit Non Metric Unit
Water activity Aw
Temperature T °C °F
Mass concentration of
water in oil ppm
NOTE ppm is only applicable to transformer oil.

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Vaisala HUMICAP®Moisture and Temperature Transmitter for Oil
MMT162 provides reliable moisture measurement in wide range of
applications. Analog outputs can be chosen between current and voltage
signals. Alternatively, digital output RS-485 comes as standard.
Basic Features and Options
- Two analog outputs
- Digital output: RS-485
- USB connectivity for service connections via the optional
USB M8 cable
- Different cable lengths available
- Available with two different thread options: ISO G1/2" and NPT 1/2"
- Low maintenance requirements due to excellent long term stability
- LED cable option that enables a visual alarm function
- Field calibration possible with MM70
- Two filter types available: stainless steel grid filter and high flow
stainless steel grid filter (>> 1 m/s)
Transmitter Structure
The structure of the MMT162 is shown in Figure 1 on page 11. The
transmitter body does not have user serviceable parts inside, and is not
designed to be opened. Opening the transmitter will void the warranty.
When the transmitter is delivered, the filter is protected by a yellow
transport protection cap. Remove the transport protection cap before
installing the transmitter.

Chapter 2 __________________________________________________________ Product Overview
VAISALA_______________________________________________________________________ 11
0805-007
Figure 1 Moisture and Temperature Transmitter for Oil
MMT162
where
1 = 4-pin M8 connector I: analog output channels and operating
power
2 = 4-pin M8 connector II (shown with protective cap):
digital output (RS-485) and operating power
3 = 30 mm nut
4 = HUMICAP®sensor protected with stainless steel grid filter
5 = Connection thread: ISO G1/2" or NPT 1/2"

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Typical Applications
Method Used for Measuring Moisture in
Oil
The MMT162 transmitter measures water in oil in terms of water activity
(aw) which can be determined as follows: water activity indicates the
amount of water on the scale of 0 - 1 aw. In this scale, 0 aw is an
indication of completely water free oil and 1 aw an indication of oil fully
saturated with water. Water is present in free form.
The most important feature which distinguishes the measurement of
water activity (aw) from the traditional measurement of absolute water
content (in ppm) is that the saturation point remains stable regardless of
the oil type or the aging of oil, additives used etc. As water activity
exceeds 0.9 aw in any system, there is a risk for segregation (especially if
the temperature decreases).
The water activity is used for alarming at the point of >0.9 aw that the
risk for free water in the system is obvious. The most important
advantages of this system are the fact that water activity is immune to the
aging of oil and to additives, and that the MMT162 transmitter can be
used for continuous on-line measurements. In addition, the MMT162 can
be calibrated against salt solutions and no reference oils are needed.
NOTE To avoid self-heating of the probe and consequential measurement
errors, make sure there is some flow in the application process.
Lubrication Oil
In many industrial plants, like paper mills, hydro power plants and off-
shore wind turbines, there is a certain amount of free moisture constantly
present. This means that there is a high risk of the free moisture
becoming into contact with the machine bearings. The most common
reasons for the entrance of water are inadequate sealing of the housing or
moisture absorbtion from ambient air. Accidental leakages from oil
coolers and other equipment can also cause damage.
Free water in lubrication oil prevents oil from forming a uniform layer on
the metal surfaces and thus deteriorating its lubrication properties. This
can cause, for example, spot heating, cavitation, corrosion and micro
pitting. Free water also ruins additives like AW (antiwear) and EP
(extreme pressure). Note that bearings should never be exposed to oils

Chapter 2 __________________________________________________________ Product Overview
VAISALA_______________________________________________________________________ 13
that have high water content; this is also important during standstill
because the risk for corrosion increases as the oil temperature decreases.
It is essential to monitor the water content and to keep it on a suitable
level, meaning below saturation.
When measuring the water content of oil, it is best to measure the water
activity before an oil reservoir and from a pressure line flow. This way
the performance of dehumidifiers can be kept under control to ensure that
no free water reaches the bearings.
Transformer Oil
The determination of moisture in oil is an essential part of a
comprehensive transformer maintenance program. Aging and
deterioration increase the capacity of oil to absorb water. The primary
interest in transformers is to measure the water not in oil but in the
cellulosic insulation around the transformer windings. Heating and
cooling have a considerable effect on moisture levels in oil. While
temperature raises, the paper insulation of transformers tends to loose
moisture which is absorbed by the oil surrounding it. Saturation level is
thus a true indicator of moisture present. The MMT162 method provides
for a reliable detection of the aging of oil and possible leakages.
Oil immersed transformers rely on the oil for cooling, protection from
corrosion and as an important component of their insulation. Excessive
moisture contents in oil causes accelerated ageing of the insulation
materials and reduces their dielectric strength. In extreme cases this can
result in arcing and short circuits within the windings. Accurate moisture
measurements can also warn about leaks in the oil system, as water is
absorbed from the surrounding air.
Heating and cooling of a transformer effect moisture levels in oil. This is
due to the fact that the water solubility of oil is temperature dependent. In
general, water solubility increases as temperature raises, see Figure 2 on
page 14 below. Changes in temperature affect also on water desorption of
the paper insulation around the transformer windings. Desorption of
water from the insulation increases as temperature raises and the
surrounded oil absorbs desorbed water. Moisture level in oil is thus a true
indicator of moisture present in the paper insulation.
In addition, it must be noted that capacity of oil to absorb water depends
both on the chemical structure of the oil and the additives.

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WATER SOLUBILITY IN MINERAL TRANSFORMER OIL
10
100
1000
10000
0 102030405060708090100
Temperature (°C)
average water
solubility
range of
variation due to
oil type
range of
variation due to
oil t
yp
e
0510-029
Figure 2 The Water Solubility of Transformer Oils versus
Temperature
The margins show the range of variation of water solubility found in
mineral oils.

Chapter 3 _______________________________________________________________ Installation
VAISALA_______________________________________________________________________ 15
CHAPTER 3
INSTALLATION
This chapter provides you with information that is intended to help you
install the product.
Installing the Transmitter
After selecting a suitable measurement location, follow the procedure
below to install the transmitter:
1. Remove the yellow transport protection cap from the transmitter.
0805-005
Figure 3 Removing the Transportation Protection Cap
2. Prepare the sealing of the connection:
-If the transmitter has a parallel ISO G1/2" thread, place the
sealing ring at the base of the thread. Always use a new
sealing ring; do not re-use a previously installed one.
- If the transmitter has an NPT 1/2" thread, do not use the
sealing ring. Instead, apply PTFE tape or suitable paste
sealant to the thread. Follow the application instructions of
the sealant.
3. Make sure that the threads on the mounting point are of the correct
type, and fasten the transmitter to the measurement point. Use your
hands to turn the probe until it feels tight. Do not use force at this
point, and check that the sealing ring
(if used) remains centered.

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0805-006
Figure 4 Installing the Transmitter
4. Use a 30 mm wrench to tighten the connection to 25 Nm, as shown
in Figure 4 above. If you do not have a 30 mm wrench, use a
1 3/16” wrench or an adjustable wrench instead.
CAUTION Only tighten the probe from the 30 mm nut. Do NOT apply force to
other points in the probe body.
5. Connect the wires of the connection cable.
0710-130
Figure 5 Connecting the Cable
6. Plug in the cable to the transmitter. Be sure to use the correct
connector; refer to section Wiring on page 17.
7. Cover the unused connector on the transmitter with the rubber plug
that is attached to the transmitter.

Chapter 3 _______________________________________________________________ Installation
VAISALA_______________________________________________________________________ 17
Wiring
Pin I II Wire Colour
1 Vcc Vcc Brown
2 Analog output 1 RS-485 B White
3 GND GND Blue
4 Analog output 2 / LED RS-485 A Black
0707-035
Figure 6 Connectors I and II
0707-036
Figure 7 Connector Pinout

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Connection Cables
The following connection cable options are available for MMT162:
- Unshielded cable with M8 female straight snap-on connector
- Shielded cables with M8 female straight threaded connector
- Shielded cables with M8 female 90° angle threaded connector
- LED cable
- USB serial interface cable
Figure 8, Figure 9, Figure 12 and Figure 10 below show the different
cable options that are available.
0510-036
Figure 8 Cable with Snap-On Connector
0510-037
Figure 9 Cable with Threaded Connector