Vaisala DRYCAP DM70 User manual

M212551EN-A
Quick 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
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Table of contents
1. Introduction to DM70....................................................................................3
1.1 Parts description...............................................................................................4
1.2 Measurement in dry environments.................................................................4
2. MI70 indicator.................................................................................................. 6
2.1 MI70 indicator parts..........................................................................................6
2.2 MI70 status icons...............................................................................................7
2.3 Installing and recharging MI70 batteries........................................................7
3. Taking measurements................................................................................... 9
3.1 MI70 first start-up settings.............................................................................. 9
3.2 Basic measuring steps with DM70..................................................................9
3.2.1 Configuring pressure settings................................................................ 10
3.2.2 Autocalibration.......................................................................................... 11
3.2.3 Sensor purge..............................................................................................11
3.3 Sampling cells.................................................................................................. 12
3.3.1 Connecting to pressurized processes using DSC74 sampling cell..... 12
3.4 Measuring multiple parameters simultaneously......................................... 14
4. User interface.................................................................................................. 16
4.1 Basic display.....................................................................................................16
4.2 Graphical display............................................................................................. 16
4.3 Main menu........................................................................................................ 17
5. Maintenance.....................................................................................................19
5.1 Changing the rechargeable battery pack.....................................................19
Maintenance and calibration services......................................................... 21
Technical support............................................................................................. 21
Warranty.............................................................................................................21
Recycling............................................................................................................ 21
Table of contents
1

DM70 Quick Guide M212551EN-A
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1. Introduction to DM70
Vaisala DRYCAPâHandheld Dew Point Meter DM70 measures dew point temperature
accurately in measurement range −60 °C … +60 °C (−76 … +140 °F), depending on the probe
model. DM70 consists of 2 main units: the MI70 indicator and DMP74 probe, models A, B, or C.
DM70 can be used with an optional sampling cell to measure process dew point. It can also be
used as a tool for reading the output of fixed Vaisala dew point transmitters, such as DMT242,
DMT132, DMT143, DMT152, and DMT340.
DM70 measures the following parameters:
Table 1 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.
This Quick Guide introduces the features of the MI70 indicator and the basic measurement
procedure with the DM70 meter.
For the full DM70 operating instructions, specifications, and more information on sampling
cells, download DM70 User Guide (M010091EN) from www.vaisala.com/dm70.
Chapter 1 – Introduction to DM70
3

1.1 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
1.2 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.
DM70 Quick Guide M212551EN-A
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• 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.
Chapter 1 – Introduction to DM70
5

2. MI70 indicator
Vaisala MI70 handheld indicator is a portable tool for viewing the measurements, recording the
data, and configuring the settings of connected Vaisala instruments. MI70 indicators can be
used with a wide range of Vaisala instruments, and are also delivered as part of the probe and
indicator product packages DM70, GM70, HM70, and MM70.
2.1 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.
DM70 Quick Guide M212551EN-A
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2.2 MI70 status icons
Icons that inform you about the status of MI70 (for example, battery status and alarm notification)
are shown on the upper left corner of the display. Multiple icons can be shown simultaneously.
Table 2 MI70 status icons
Icon 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
The battery can no longer be charged 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).
Recording icon. Shows that the measurements are being recorded. The bar
shows for how long the recording will continue (a set time limit or until the
memory runs out). The recording icon and bar are shown also when the
indicator is powered o.
Calibration reminder icon. Appears when a calibration reminder has been set
to inform that a user-defined interval has passed and calibration is due.
Analog output icon. Shown when the analog output mode is in use.
PC connection icon. Shown when the indicator is connected to a PC with a
cable.
Alarm icon. Shown when the measurement has reached a user-defined alarm
limit.
2.3 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.
Chapter 2 – MI70 indicator
7

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 Table 2 (page 7).
To recharge the rechargeable battery:
1. Plug in the charger connector to the MI70 indicator. The socket is located at the top of the
indicator, covered by a rubber seal.
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
capacity.
Do not store the batteries empty. Empty batteries may not charge after an
extended storage period.
To keep the rechargeable MI70 battery in good working condition, recharge
MI70 monthly if the indicator is not in use.
DM70 Quick Guide M212551EN-A
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