Vaisala DRYCAP DM70 User manual

M010091EN-G
User Guide
Vaisala DRYCAPâHandheld Dew Point Meter
DM70

PUBLISHED BY
Vaisala Oyj
Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland
P.O. Box 26, FI-00421 Helsinki, Finland
[phone]
Visit our Internet pages at www.vaisala.com.
© Vaisala 2020
No part of this document may be
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Translated documents and translated
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Vaisala makes no representations on this
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customers or end users. All legally binding
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exclusively in the applicable supply
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and General Conditions of Service of
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This product contains software developed
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supply contract or, in the absence of
separate license terms and conditions, by
the General License Conditions of Vaisala
Group.

Table of contents
1. About this document.....................................................................................7
1.1 Version information.......................................................................................... 7
1.2 Related manuals................................................................................................7
1.3 Documentation conventions........................................................................... 8
1.4 Trademarks........................................................................................................ 8
2. Product overview............................................................................................ 9
2.1 Introduction to DM70....................................................................................... 9
2.2 Basic features and options.............................................................................10
2.3 Parts description...............................................................................................11
3. MI70 indicator................................................................................................. 12
3.1 MI70 indicator parts........................................................................................ 12
3.2 Installing and recharging MI70 batteries...................................................... 12
3.2.1 MI70 battery status information.............................................................13
3.3 MI70 first start-up settings.............................................................................14
3.4 Changing the rechargeable battery pack.....................................................14
4. Dew point measurement............................................................................ 16
4.1 Measurement in dry environments................................................................16
4.2 Taking dew point measurements.................................................................. 16
4.3 Measuring multiple parameters simultaneously..........................................17
5. User interface.................................................................................................. 19
5.1 Basic display.....................................................................................................19
5.2 Main menu........................................................................................................ 19
5.3 MI70 status icons............................................................................................ 22
5.4 Display menu...................................................................................................23
5.4.1 Selecting parameters and units.............................................................23
5.4.2 Rounding..................................................................................................24
5.4.3 Holding and saving the display............................................................. 24
5.4.4 Graphical display..................................................................................... 25
5.5 Functions menu.............................................................................................. 25
5.5.1 Setting an alarm...................................................................................... 25
5.5.2 Selecting and scaling analog output.................................................... 26
5.5.3 Autocalibration........................................................................................ 27
5.5.4 Sensor purge.............................................................................................31
5.6 Recording/Viewing menu..............................................................................33
5.6.1 Recording data........................................................................................ 33
5.6.2 Viewing recorded data........................................................................... 34
5.6.3 Checking MI70 memory status..............................................................34
5.6.4 Clearing data memory............................................................................34
5.6.5 Transferring recorded data to PC with MI70 Link............................... 35
5.7 Environment menu.........................................................................................35
5.7.1 Configuring pressure settings................................................................35
Table of contents
1

5.8 Settings menu.................................................................................................36
5.8.1 User interface settings............................................................................36
5.9 Date and time..................................................................................................38
5.10 Measurement settings................................................................................... 39
5.11 Setting calibration reminder......................................................................... 39
5.12 Device information........................................................................................ 40
5.13 Factory settings...............................................................................................41
6. Field calibration check of fixed transmitters.................................... 42
6.1 Field calibration check of DMT340/DMT242/DMT143.............................. 42
7. Sampling from processes..........................................................................44
7.1 Sampling cells.................................................................................................44
7.1.1 DSC74....................................................................................................... 44
7.1.2 DSC74B.....................................................................................................45
7.1.3 DSC74C.....................................................................................................46
7.1.4 DMT242SC and DMT242SC2..................................................................47
7.2 Connecting to pressurized processes using DSC74 sampling cell........... 48
7.3 DSS70A sampling system...............................................................................51
7.3.1 DSS70A sampling procedure.................................................................52
7.3.2 Recharging DSS70A battery..................................................................53
7.3.3 Changing DSS70A battery.....................................................................54
7.3.4 Changing DSS70A filter..........................................................................56
7.3.5 Changing DSS70A fuses.........................................................................57
8. Measuring moisture in SF6gas-insulated equipment .................. 58
8.1 Overview..........................................................................................................58
8.2 Operating environment................................................................................. 59
8.3 Measuring........................................................................................................ 59
9. Calibration and adjustment.......................................................................61
9.1 Calibration........................................................................................................ 61
9.2 User calibration and adjustment................................................................... 61
9.3 Adjusting DM70............................................................................................... 61
9.4 Adjusting DMT340 series transmitters using DM70 as
reference or terminal......................................................................................62
9.5 Adjusting dew point.......................................................................................62
9.5.1 Making a 2-point relative humidity adjustment.................................. 62
9.5.2 Making a 2-point %RH adjustment of DMT340 series
transmitters using DM70........................................................................64
9.5.3 Td/f adjustment of DM70....................................................................... 65
9.5.4 Td/f adjustment of DMT340 series transmitters using DM70........... 66
9.6 Adjusting temperature...................................................................................68
9.6.1 Temperature adjustment of DM70........................................................ 68
9.6.2 Temperature adjustment of DMT340 series using DM70.................. 70
10. Technical data................................................................................................ 73
10.1 DM70 and DMP74 specifications.................................................................. 73
DM70 User Guide M010091EN-G
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10.2 MI70 specifications.........................................................................................78
10.3 Dimensions..................................................................................................... 80
10.4 Spare parts and accessories......................................................................... 80
Maintenance and calibration services........................................................ 83
Technical support............................................................................................ 83
Warranty............................................................................................................ 83
Recycling........................................................................................................... 83
Table of contents
3

List of figures
Figure 1 DM70 parts......................................................................................................... 11
Figure 2 MI70 indicator parts........................................................................................ 12
Figure 3 Display example with carbon dioxide and temperature
and humidity probes connected simultaneously....................................18
Figure 4 DM70 basic display..........................................................................................19
Figure 5 DM70 menus......................................................................................................21
Figure 6 Quantities and units menu............................................................................23
Figure 7 Analog output menu...................................................................................... 27
Figure 8 Sensor purge displays....................................................................................33
Figure 9 Recording/Viewing menu.............................................................................34
Figure 10 User interface settings menu.......................................................................36
Figure 11 Hold/Save replaced by AutoCal..................................................................38
Figure 12 Measurement settings menu....................................................................... 39
Figure 13 Calibration reminder menu..........................................................................40
Figure 14 Device information menu.............................................................................40
Figure 15 Indicator and probe information................................................................. 41
Figure 16 DSC74 sampling cell with adapters........................................................... 45
Figure 17 DSC74B..............................................................................................................46
Figure 18 Default assembly of DSC74C.......................................................................46
Figure 19 Alternative assembly of DSC74C for tight spaces................................. 47
Figure 20 DMT242SC and DMT242SC2 sampling cells............................................47
Figure 21 Turning sampling cell valve screw with flathead screwdriver............50
Figure 22 DSSA70A portable sampling system.........................................................52
Figure 23 Lifting the system........................................................................................... 54
Figure 24 Sampling system upside down....................................................................55
Figure 25 Changing the filter..........................................................................................56
Figure 26 Gas collection option..................................................................................... 58
Figure 27 Removing the leak screw..............................................................................59
Figure 28 DMP74A dew point accuracy vs. measurement conditions................ 75
Figure 29 DMP74B and DMP74C dew point accuracy vs.
measurement conditions.............................................................................. 75
Figure 30 Dimensions of MI70 indicator, DMP74 probe, DSC74
sampling cell, and DSC74C sampling cell (left to right
and top to bottom)........................................................................................ 80
DM70 User Guide M010091EN-G
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List of tables
Table 1 Document versions (English)............................................................................ 7
Table 2 Related manuals................................................................................................... 7
Table 3 Display parameters..............................................................................................9
Table 4 MI70 battery status indicator.......................................................................... 13
Table 5 MI70 status icons................................................................................................22
Table 6 DM70 handheld meter general specifications........................................... 73
Table 7 DMP74A, DMP74B, and DMP74C measurement performance.............. 73
Table 8 DMP74A, DMP74B, and DMP74C general specifications.........................75
Table 9 DMP74A, DMP74B, and DMP74C mechanical specifications................. 76
Table 10 Sampling cell specifications............................................................................76
Table 11 MI70 measurement indicator..........................................................................78
Table 12 MI70 battery operation time...........................................................................79
Table 13 DM70 spare parts and accessories............................................................... 80
List of tables
5

DM70 User Guide M010091EN-G
6

1. About this document
1.1 Version information
This document provides detailed instructions for using and maintaining Vaisala DRYCAPâ
Handheld Dew Point Meter DM70.
Table 1 Document versions (English)
Document code Date Description
M010091EN-G October
2020
This document.
• The following sections added:
•MI70 battery status information (page 13)
•MI70 status icons (page 22)
•Setting calibration reminder (page 39)
• The following sections updated:
• Sections introducing the MI70 indicator
•Measuring multiple parameters simultaneously (page 17)
•Connecting to pressurized processes using DSC74 sampling
cell (page 48)
•Calibration (page 61)
•DM70 and DMP74 specifications (page 73)
•Spare parts and accessories (page 80)
• References to DMP248 removed
• Document format and layout update, quality improvements,
and content reorganization.
M010091EN-F September
2007
Previous version.
1.2 Related manuals
Table 2 Related manuals
Document code Name
M210704EN Vaisala DRYCAP â Dewpoint and Temperature Transmitter Series DMT340 User's
Guide
Chapter 1 – About this document
7

1.3 Documentation conventions
Warning alerts you to a serious hazard. If you do not read and
follow instructions carefully at this point, there is a risk of injury or even death.
WARNING!
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.
CAUTION!
Note highlights important information on using the product.
Tip gives information for using the product more eciently.
Lists tools needed to perform the task.
Indicates that you need to take some notes during the task.
1.4 Trademarks
Vaisalaâand DRYCAPâare registered trademarks of Vaisala Oyj.
Windowsâis either a registered trademark or trademark of Microsoft Corporation in the
United States and other countries.
DM70 User Guide M010091EN-G
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2. Product overview
2.1 Introduction to DM70
Vaisala DRYCAPâHandheld Dew Point Meter DM70 measures dew point temperature
accurately in a measurement range from −60 °C up to +60 °C (−76 ... +140 °F) depending on
the probe model. DM70 incorporates the advanced DRYCAPâtechnology, which enables
reliable and high-performance dew point measurement. DM70 measures the following
parameters:
Table 3 Display parameters
Parameter Abbreviation Metric unit Non-metric unit
Relative humidity RH %RH %RH
Temperature T °C °F
Dew point/frost point
temperature 1)
Td/f °C °F
Dew point temperature
2)
Td°C °F
Dew point in the
atmospheric pressure
Td°C atm °F atm
Dew point/frost point
in the atmospheric
pressure
Td/f °C atm °F atm
Absolute humidity a g/m3gr/ft3
Mixing ratio x g/kg gr/lb
Water concentration /
Water mass fraction
H2O ppmv/ ppmwppmv/ ppmw
1) Td/f shows dew point temperature above the freezing point (0 °C/32 °F) and frost point
temperature Tf(dew point over ice) below the freezing point. This is considered as the
industry standard.
2) Tdshows dew point over water throughout the entire measurement range.
DM70 consists of 2 main units: the MI70 indicator and DMP74 probe, models A, B, or C. DM70
can be used with the optional sampling cell to measure process dew point. With DSS70A,
DM70 forms a part of a complete portable sampling system for measuring process dew point.
Chapter 2 – Product overview
9

More information
‣DM70 and DMP74 specifications (page 73)
‣Parts description (page 11)
‣Sampling cells (page 44)
2.2 Basic features and options
DM70 has the following basic features and options:
• Numerical and graphical multilingual displays
• Data recording possibility
• Three probe models, temperature measurement range −60 … +60 °C (−76 … +140 °F),
depending on the model
• A tool for checking the reading of fixed transmitters DMT340, DMT242, and DMT143
• A possibility for an analog output (voltage signal 0 ... 1 V)
• Multiprobe operation; any combination of 2 Vaisala DM70, GM70, HM70, and MM70 series
probes can be used, for example, for simultaneous dew point and relative humidity
measurements
• The optional, ready-to-use MI70 Link Microsoft Windowsâsoftware, which allows an easy
way to handle measurement data using a serial line or a USB instrument cable
• The optional sampling system DSS70A
More information
‣DSS70A sampling system (page 51)
‣Transferring recorded data to PC with MI70 Link (page 35)
DM70 User Guide M010091EN-G
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2.3 Parts description
6
5
4
2
3
1
Figure 1 DM70 parts
1Charger socket
2MI70 indicator
3Connector ports for probes and cables
4Calibration button
5Sampling cell DSC74 (optional)
6DMP74 probe
Chapter 2 – Product overview
11

3. MI70 indicator
3.1 MI70 indicator parts
6
5
4
3
2
1
Figure 2 MI70 indicator parts
1Charger socket
2Function key shortcut buttons . The
functions change according to what
you are doing with the indicator.
3Arrow buttons:
Move up in a menu
Move down in a menu
Enter a sub-menu
Return to previous menu level
4Power On/O button
5Battery compartment at the back of
the indicator
62 ports (labeled I and II) for
connecting probes and instruments.
To open menus, press an arrow button and then press the shortcut buttons. To activate a
function shown above the shortcut button, press the shortcut button. To navigate in the
menus, press the arrow buttons.
3.2 Installing and recharging MI70 batteries
If you are using alkaline batteries, unscrew the back plate of the indicator and insert the
batteries. Do not attempt to recharge standard alkaline batteries.
If you ordered MI70 with a rechargeable battery, it is already in place as shipped from the
factory. The delivered batteries have been pre-charged.
To recharge the battery:
1. Plug in the charger connector to the indicator. The socket is located at the top of the
indicator, covered by a rubber seal.
DM70 User Guide M010091EN-G
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2. Connect the charger to a wall socket. An animated battery icon in the left corner of the
display indicates that the battery is charging. The recharge duration (typically 4 ... 5 h)
depends on the charge level of the battery.
A new battery takes approximately 3 charging cycles to reach its maximum
battery life.
Do not store the batteries empty. Empty batteries may not charge after an
extended storage period.
3.2.1 MI70 battery status information
The status of the MI70 battery is shown by the battery icon in the upper left corner of the
display. Possible statuses are listed in the following table.
Table 4 MI70 battery status indicator
Battery status indicator
graphic
Description
Battery status icon. The icon can show the following info:
• 0 ... 8 bars, no animation:
• batteries are in use, a charger is not connected
• if a charger is connected: non-rechargeable batteries installed
• if a charger is connected: waiting for the battery temperature to
settle between 0 ... +40 °C (+32 ... +104 °F)
• if a charger is connected and the icon remains at 8/8 bars: the
battery is full
• Animated battery status icon: battery is charging (or recovering
after emptying out completely). The charging animation is shown
also when the indicator is powered o.
• Battery icon not present: batteries are not installed
An empty battery icon with an X over it means that the battery
cannot be recharged and must be replaced. If the indicator is
powered on, a notification about not being able to charge the
battery is shown on the MI70 screen.
You can order replacement batteries from Vaisala (item code 26755).
To keep the rechargeable MI70 battery in good working condition, recharge MI70
monthly if the indicator is not in use.
Chapter 3 – MI70 indicator
13

More information
‣Spare parts and accessories (page 80)
3.3 MI70 first start-up settings
When you switch on MI70 for the first time, configure the basic settings (time, date, language)
as instructed below.
1. Connect the probe to either one of the base connectors in the indicator. To ensure a
durable connection, screw the metal ring clockwise until it tightens up. (Respectively,
when disconnecting the cable, first screw the metal ring counterclockwise until it loosens
and then pull out the plug.)
2. Press the Power On/O button.
3. Press any of the arrow buttons and open the menu by pressing Open.
4. Select Settings using the buttons and press .
5. Select User interface and press .
6. Select Language and press Set.
7. Select the language using the buttons. Confirm the selection by pressing Select.
8. If you want to set the date at this point, return to the Settings menu by pressing .
The language can be selected also later. For instructions, see Selecting
language (page 36).
9. To change the date, select Date and press Set. Then change the date using the
buttons. To confirm the selection, press Select. As a default, the date format is year-
month-day. You can select from 2 other alternative formats.
10. To change the time, select Time and press Set. Then change the time by using the
arrow buttons. Confirm the selection by pressing OK. As a default, the time format is
based on the 24-hour clock. If you want to use the 12-hour clock, select 12-hour clock and
then press On.
11. To return to the basic display, press Exit.
3.4 Changing the rechargeable battery pack
• New rechargeable battery pack
• Medium-sized flathead screwdriver
DM70 User Guide M010091EN-G
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In case you are installing a battery pack and you have a device with alkaline batteries, remove
the metal contact from the probe port end of the battery compartment before installing the
battery pack.
1. Open the back plate of the indicator by opening the screw of the back plate.
2. Remove the old battery pack. Detach the black connector by carefully pulling it up from
the wires.
3. Connect the black connector of the new battery pack. Make sure the position of the
connector is as shown in the following figure (red and black wires are on the upper edge
of the connector). Do not push the connector with conducting material.
4. Place the battery pack in the compartment.
5. Close the back plate and tighten the screw.
6. Recharge the indicator before use.
Chapter 3 – MI70 indicator
15

4. Dew point measurement
4.1 Measurement in dry environments
The following recommendations should be taken into account when measuring in very dry
environments:
• A clean environment is always best for humidity measurements.
• The number of connections should be minimized to avoid leaks.
• The flow rate must be adequate.
• Dead ends must be avoided as they cannot be flushed easily.
• The tube temperature must never lie under the dew point of the sample gas. This may
lead to condensation and false results.
• The sample tubing should be of as short length as possible. The surface area should be
minimized using the narrowest tubing that the flow conditions allow.
• The surface finish of the pipework is important. Polished or electro-polished steel is
recommended for best results.
• Hygroscopic materials should be avoided in the sampling lines. Use stainless steel
membranes instead of rubber membranes.
• Impermeable materials should be selected to avoid inward diusion of moisture through
the sampling tubes and enclosures. Such impermeable materials are, for example, high-
quality stainless steel and metals. Avoid PVC or nylon tubes.
4.2 Taking dew point measurements
When you start to use DM70 for the first time, see MI70 first start-up settings (page 14).
Otherwise follow the instructions below.
1. Connect the probe to the MI70 indicator.
2. Press the Power On/O button.
3. Install the probe to the measuring position. If you are measuring in pressurized processes,
see Connecting to pressurized processes using DSC74 sampling cell (page 48). When
using other sampling cells than DSC74, make sure that the threads are compatible with
the probe threads (G ½" ISO228/1). Be careful not to damage the sintered filter when
installing the probe.
4. Before measuring, make sure that the air pressure settings of DM70 are correct and that
autocalibration has taken place (see Automatic autocalibration (page 28)).
DM70 User Guide M010091EN-G
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5. The basic display opens. Let the reading stabilize.
If you need to disconnect the probe from the indicator, first
press the Power On/O button to turn the indicator o. This ensures that
all the settings and data are saved properly
CAUTION!
When measuring low dew points, the stabilization times can be long, for
example, 1 ... 2 hours. Therefore, turn o the automatic power-o function,
turn on the automatic autocalibration, and turn on the automatic sensor
purge.
This allows monitoring the stabilization, the autocalibration ensures an
accurate measurement, and the purge ensures the shortest possible response
times.
More information
‣Configuring automatic power o (page 37)
‣Turning automatic autocalibration on and o (page 28)
‣Turning automatic sensor purge on and o (page 31)
4.3 Measuring multiple parameters simultaneously
MI70 is a generic indicator that can be used with Vaisala interchangeable dew point
(DM70 series), humidity (HM70 series), carbon dioxide (GM70 series), and moisture in oil
(MM70 series) probes. Two dierent types of probes can be connected to MI70 simultaneously.
1. Switch o the MI70 indicator.
2. Connect the 2 probes to the connector ports (port I and II) on the bottom of the indicator.
3. Switch on MI70.
4. Check that the environment settings of the probes (port I and II) are the same if you are
taking measurements from the same condition. In this case, select Yes when MI70
prompts you to check the environment settings.
Chapter 4 – Dew point measurement
17

5. The reading of the probe in port I is now displayed on the upper row(s) and the reading of
the probe in port II on the lower row(s) of the MI70 display.
Figure 3 Display example with carbon dioxide and temperature and humidity probes
connected simultaneously
DM70 User Guide M010091EN-G
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