Retrotec DM2MkII User manual

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QuickGuide‐DM2MkIIDigitalGauge
Rev 2009-02-02
The DM-2 has two independent differential-pressure
sensors (Channel A and B) plus an automatic
controller that will control a compatible fan.
Channel A always displays the difference in
pressure between the blue “Input A(+)” and the red
“Ref A(-)” in units of Pascals, inches of water or
pounds per square foot. “PrA” on the screen refers
to Pressure on channel A.
Channel B may similarly indicate pressure (between
“Input B(+) and Ref B(-)) when “PrB” is displayed.
When a flow device is connected, this pressure can
be converted to flow when the correct flow Device
and results Mode is selected.
Getting Started
Perform each step in sequence to learn the purpose of each
key and set up the DM-2 for the correct application.
For further information refer to Manual-DM2MkII
1 Unpack the DM-2 kit
The kit contains:
1.1 1 - DM-2 Gauge.
1.2 4 - AA NiMH Batteries installed.
1.3 1 - AC power adapter.
1.4 Laptop-style case.
1.5 1 – Computer interface cable (mini-USB to
USB).
Note: additional tubes and cables may be included.
2 Charge batteries overnight
2.1 Remove battery compartment cover on back
of DM-2, install 4 NiMH batteries and replace
cover.
2.2 Plug the AC power adapter into the back of
the DM-2 and into the wall.
2.3 Press [On/Off] and the Retrotec screen
should appear:
Note The DM-2 will not start charging unless it is turned on.
2.4 Press [Exit] to advance to the main screen.
2.5 Allow batteries to charge 12 hours.
2.6 The battery indicator in the top left corner will
be solid black when fully charged.
2.7 Unplugging the charger for day to day use to
will protect the charging socket from damage,
maintain a constant screen contrast, improve
backlight performance and allow the batteries
to discharge thereby increasing battery life.
2.8 Press and hold [On/Off] until the DM-2 turns
off.
Note If the DM-2 is turned off after AC power is connected, the
message “Charging ...” is displayed on the screen until
charging is complete.

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3 Turn gauge on
[On/Off] turns the DM-2 on and off and
turns the backlight on and off.
3.1 Press [On/Off] to turn the DM-2 on.
3.2 Press any button to clear the Retrotec screen.
To use the backlight:
3.3 When the backlight is off, press any button to
turn the light on for 15 seconds.
3.4 Press [On/Off] to turn the display backlight on
permanently.
3.5 Press [On/Off] a second time to turn the
backlight off.
Tip Leaving the backlight on discharges the battery at a faster
rate.
4 Locate the [Exit] button
[Exit] backs out of menus, cancels data
input and stops the various control modes.
4.1 Press [Exit] to:
•Clear the splash screen.
•Stop the fan and cancel [Set Speed] mode.
•Stop the fan and cancel [Set Pressure]
mode.
•Clear and cancel [Baseline] mode.
•Move back or exit the [Setup] menus.
•Cancel Volume and Area inputs.
•Cancel other data entry.
5 Scroll through the enabled fans
[Device] selects a fan. The DM-2 currently supports
all Retrotec, Energy Conservatory and Infiltec fans.
Choosing the correct fan is required for accurate
results data.
5.1 Press [Device] repeatedly to scroll through
the enabled fans.
Note From the factory, the Retrotec DU200, Retrotec 2000,
Retrotec 3000 and Retrotec 3000SR are enabled. All
other fans are disabled.
Tip To reduce confusion and errors, disable fans that won’t be
used, in the [Setup] menu. See section 17.
6 Scroll through fan ranges
[Range Config] is used to select the range
configuration of the selected fan. Selecting the
correct range is required to achieve correct results.
6.1 Press [Range Config] repeatedly to scroll
through the possible range plate
configurations for the currently selected
device.
Note Flow and other results will be calculated based on the flow
equations for the selected fan and range. Refer to the
Flow curve or Range Configuration chart for a particular
fan (such as “QuickGuide-RangeConfig2000&3000.pdf”).
7 Scroll through the enabled results
[Mode] selects the results that are to be displayed.
The DM-2 supports on-the-fly calculation of almost
any measurement that might be needed including
Flow, Air Changes, Leakage Areas and many
others.
7.1 Press [Mode] repeatedly to scroll through the
enabled results.
Note By default, Flow, Air Changes, and EqLA are enabled. All
other results are disabled.
Tip To reduce confusion and errors, disable results that won’t
be used. See section 18.
8 Explore time averaging
When time averaging is active, the DM-2 will display
results and pressures that are averaged over the
selected time period.
Note 1s, 2s, 4s, 8s: Display updates every 1 second.
10s, 20s, 1min, 2min: Display updates every 10 seconds.

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9 Hold / Jog
[Jog/Hold] will “freeze” the display when “Hold” is
displayed, and allow adjustment of the speed or
target pressure when “Jog” is displayed.
9.1 Press [Jog/Hold] until “Hold” appears. The
display will be frozen with the current values.
9.2 Press [Jog/Hold] or [Exit] to cancel display-
hold.
9.3 Press [Jog/Hold] until “Jog” appears. The
[S] [T] buttons will adjust the speed (in Set
Speed mode) or pressure (in Set Pressure
mode) up or down.
Note “Jog” is only available in the Set Speed or Set Pressure
mode.
10 @ Pressure
Fig 1 – Fan adjusted to
achieve exactly 50 Pa
Fig 2 – Fan adjusted to
achieve about 50 Pa
Fig 3 – @-mode enabled to
estimate flow @ 50 Pa
10.1 [@ Pressure] provides an estimate of the
results (e.g. Flow) at a target pressure, even if
the target pressure cannot be reached.
10.2 [@ Pressure] has no effect when mode is
“PrB”.
10.3 Press [@ Pressure] until “@50 Pa” appears
under “cfm”. Results are displayed for 50 Pa,
even if the pressure is not 50 Pa.
11 Discover AutoZero
When Auto Zero is active, the gauge will
automatically zero itself every 8 seconds.
11.1 Press [Auto Zero] until “On” appears.
Tip AutoZero should be left ‘On’ under normal operation.
12 The [Enter] key
The [Enter] key is used to acknowledge
inputs and to allow data entry.
12.1 Press [Enter] to:
•Change volume in Air Chg mode.
•Change area in Flow/Area and
Leakage/Area modes.
•Accept the indicated Baseline pressure.
•Accept the input fan speed or PrA pressure.
13 Learn about Baseline mode
Press [Exit] to clear any previous menus or settings.
When Baseline mode is active, PrA will be
continuously adjusted to remove the average
background pressure.
13.1 Press [Baseline] once. The DM-2 will begin
sampling the background pressure (see Fig 1).
13.2 After the desired amount of time has passed,
press [Enter].
13.3 The average baseline pressure is displayed in
the upper left corner of the DM-2.
13.4 Press [Exit] to clear the calculated baseline.
Tip When [Exit] stops the fan, the baseline value is erased.

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14 Manually set fan speed
Use to set fan speed on any Retrotec “Q”
system or any other system using the
Retrotec Q Automatic Adapter.
See: The QuickGuide for the system in use.
15 Automatically control to a pressure
Use to control the pressure on any
Retrotec “Q” system or any other system
using the Retrotec Q Automatic Adapter.
When the pressure is set to “0”, the fan
will speed up to force the existing pressure to zero. Do
not have “@” showing after flow when using set to zero.
See: The QuickGuide for the system in use.
16 Set up gauge
16.1 Press [Setup] [T] to view the main setup
menu. Stop at:
16.2 “n”, sets the slope of the @-Pressure
extrapolation line. Use 0.65 for tight houses
and 0.60 for ducts and large buildings. Press
[Enter][0.6 to 0.65 ][Enter].
Press [T] once to see:
16.3 “Power Down Hour”. Enter a value to
determine how long the DM-2 remains inactive
before automatically turning off. Press [Enter]
[2] [Enter] to have the DM-2 turn off in two
hours. The DM-2 will never turn off if a value
of “0” is entered. Press [T] once to see:
16.4 “Surface Area Unit” for building envelope or
floor areas used in Flow or Leakage Area /
Building Area results. Press [X] until the
desired units for building area appear.
Press [T] to see:
16.5 “Building Volume Unit” units for air-change
calculations. Press [X] until the desired units
for building volume appear. Press [T] to see:
16.6 “European , Separator” Press [X],
“No” displays one thousand as “1.000”,
“Yes” displays one thousand as “1,000”.
Press [T] to see:
16.7 “Sig Figs” Press [X]to change the number of
significant figures displayed.
16.8 Press [Exit] to return to the main screen.
17 Add/Remove fans
The Device Setup sub-menu allows fans to be
added or removed. Eliminate all unused fans avoid
mistakes.
17.1 Press [Setup] and then [T] until “Device
Setup” appears. Then press [Enter] to view
fans available when [Device] is used.
17.2 Press [T] to scroll down through fans. Press
[X] until “Yes” appears beside the fans that
may be used. Select “No” beside the fans that
won’t be used. For Retrotec Systems: R43,
E43, Q46 and Q56 select ‘Retrotec 2000’.
Q4E, Q5E and QMG without green tube
connected,select ‘Retrotec 3000’. 3000 fans
with green flow tube connected, select
‘Retrotec 3000SR’.
System: Q32, R31 select ‘Retrotec DU200’.
17.3 Disabled fans will not appear when [Device] is
used but may be added back in later.
17.4 Press [Exit] twice to return to the main screen.
Note At least one fan must be enabled for correct DM-2
behavior!
18 Enable/disable results
Use the Mode Setup sub-menu to enable and
disable the various results (Flow, EqLA, ACH, etc),
to select units and to change the @-Pressures.
18.1 Press [Setup] and then [T] until “Mode
Setup” appears. Press [Enter] to view all
available results available when the [Mode]
key is used.
18.2 Press [T] to scroll down through possible
results and stop at “Pressure”. Press [X] to
select units.
18.3 Press [T] to select “Flow”. Press [X] to
select flow units or select “Off” so flow does
not appear when the [Mode] key is used.
18.4 Press [T] to select “@Pressure” which is the
pressure at which the results above will be
extrapolated to when the [@] key is used.
18.5 Press [Enter] [4 to 70] to change the “@
Pressure” or just leave the default value.
18.6 Similarly, add needed results and remove the
rest to save time during tests. Change “@
Pressure” if required, otherwise use the
original default value.
18.7 Disabled results will not appear when the
[Mode] key is used but may be added back in
if needed.
18.8 Press [Exit] twice to return to the main screen.
Note Pressure cannot be disabled. All other results can be
disabled.