TEC DG-700 User manual

Operating Instructions for the
DG-700
Pressure and Flow Gauge

Operating Instructions for the
DG-700
Pressure and Flow Gauge
The Energy Conservatory
2801 21st Ave. S., Suite 160
Minneapolis, MN 55407
Ph.: [phone]
Fax: [phone]
www.energyconservatory.com

Manual Edition May 2012
2012 The Energy Conservatory. All rights reserved.
ENERGY CONSERVATORY WARRANTY
EXPRESS LIMITED WARRANTY:
Seller warrants that this product, under normal use and service as described in the operator’s manual, shall be free from defects in workmanship
and material for a period of 24 months, or such shorter length of time as may be specified in the operator’s manual, from the date of shipment to
the Customer.
LIMITATION OF WARRANTY AND LIABILITY:
This limited warranty set forth above is subject to the following exclusions:
a) With respect to any repair services rendered, Seller warrants that the parts repaired or replaced will be free from defects in workmanship
and material, under normal use, for a period of 90 days from the date of shipment to the Purchaser.
b) Seller does not provide any warranty on finished goods manufactured by others. Only the original manufacturer’s warranty applies.
c) Unless specifically authorized in a separate writing, Seller makes no warranty with respect to, and shall have no liability in connection
with, any goods which are incorporated into other products or equipment by the Purchaser.
d) All products returned under warranty shall be at the Purchaser’s risk of loss. The Purchaser is responsible for all shipping charges to return
the product to The Energy Conservatory. The Energy Conservatory will be responsible for return standard ground shipping charges. The
Customer may request and pay for the added cost of expedited return shipping.
The foregoing warranty is in lieu of all other warranties and is subject to the conditions and limitations stated herein. NO OTHER EXPRESS
OR IMPLIED WARRANTY IS PROVIDED, AND THE SELLER DISCLAIMS ANY IMPLIED WARRANTY OF FITNESS FOR
PARTICULAR PURPOSE OR MERCHANTABILITY.
THE EXCLUSIVE REMEDY OF THE PURCHASER FOR ANY BREACH OF WARRANTY shall be the return of the product to the factory
or designated location for repair or replacement, or, at the option of The Energy Conservatory, refund of the purchase price.
The Energy Conservatory’s maximum liability for any and all losses, injuries or damages (regardless of whether such claims are based on
contract, negligence, strict liability or other tort) shall be the purchase price paid for the products. IN NO EVENT SHALL THE SELLER BE
LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES. The Energy Conservatory shall not be responsible for
installation, dismantling, reassembly or reinstallation costs or charges. No action, regardless of form, may be brought against the Seller more
than one year after the cause of action has accrued.
The Customer is deemed to have accepted the terms of this Limitation of Warranty and Liability, which contains the complete and exclusive
limited warranty of the Seller. This Limitation of Warranty and Liability may not be amended or modified, nor may any of its terms be waived
except by a writing signed by an authorized representative of the Seller.
TO ARRANGE A REPAIR: Please call The Energy Conservatory at 612-827-1117 before sending any product back for repair or to inquire
about warranty coverage. All products returned for repair should include a return shipping address, name and phone number of a contact person
concerning this repair, and the purchase date of the equipment.

Table of Contents
CHAPTER 1 FEATURE SUMMARY 1
1.1 Feature List 1
1.1.a Pressure Measurements: 1
1.1.b Auto Zeroing: 1
1.1.c Time Averaging: 1
1.1.d Air Flow and Velocity Measurements: 1
1.1.e Display “HOLD”: 1
1.1.f Specialized @ 50 and @ 25 Leakage Measurement Mode: 2
1.1.g Specialized Air Handler Flow Measurement Mode: 2
1.1.h Automated Blower Door Testing, Cruise Control and Data Logging: 2
1.2 Overview of Gauge Operating Modes 2
1.3 Gauge Face and Buttons 3
1.4 Input/Output Ports on the DG-700 4
1.4.a USB and Serial Communication Ports: 4
1.4.b Fan Control Output Jack: 4
1.4.c AC Power Input Jack: 4
1.5 Overview of the Time Averaging Feature 5
1.5.a Description of Time Averaging Periods: 5
1.5.b Illustration of Time-Averaging Operation (First 10 seconds of operation): 5
1.5.c Resetting the Time Averaging Measurement Buffer: 5
1.6 Overview of the Baseline Pressure Measurement Feature (Channel A) 6
1.6.a Buttons Used with Baseline Pressure Feature: 6
1.6.b Restarting the Baseline Measurement: 7
1.6.c Clearing and Exiting from the Baseline Pressure Procedure: 7
1.7 Auto-Off Feature 7
CHAPTER 2 PRESSURE/PRESSURE MODE 8
2.1 Mode Summary 8
2.2 Overview of Pressure/Pressure Mode 8
2.3 Changing the Pressure Units 8
2.4 Changing the Time Averaging Period 9
2.5 Using the Baseline Pressure Feature 9
2.5.a Example: Measuring Building Depressurization from an Exhaust Fan 9
CHAPTER 3 PRESSURE/FLOW MODE 11
3.1 Mode Summary 11
3.2 Overview of Pressure/Flow Mode 11
3.3 Changing the Selected Test Device and Configuration 11
3.4 “LO” Displayed on Channel B 12
3.5 Changing the Air Flow Units 12
3.6 Changing the Time Averaging Period 12
3.7 Using the Baseline Pressure Feature in Pressure/Flow Mode 12
3.7.a Example: Using the Baseline Feature During a Blower Door Depressurization Test 12

3.7.b Entering Baseline Readings into TECTITE Software When Using the Baseline Feature: 13
CHAPTER 4 PRESSURE/FLOW @ 50 AND @ 25 MODES 14
4.1 Mode Summary 14
4.2 Overview of Pressure/Flow @ 50 and @ 25 Modes 14
4.2.a Pressure/Flow @ 50 Mode: 14
4.2.b Pressure/Flow @ 25 Mode: 14
4.2.c Benefits of Using the @ 50 and @ 25 Modes: 15
4.3 Changing the Selected Test Device and Configuration 15
4.4 “-----”or “LO” Displayed on Channel B 15
4.5 Changing the Leakage Units 16
4.6 Changing the Time Averaging Period 16
4.7 Using the Baseline Pressure Feature in Pressure/Flow Mode 16
4.8 Leakage Estimate Calculations Used in the @ 50 and @ 25 Modes 16
4.8.a @ 50 Mode: 16
4.8.b @ 25 Mode: 17
4.8.c Errors in Leakage Estimates: 17
CHAPTER 5 PRESSURE/AIR HANDLER FLOW MODE 19
5.1 Mode Summary 19
5.2 Overview of Pressure/Air Handler Flow Mode 19
5.3 Changing the Selected Test Device and Configuration 19
5.4 “-----”or “LO” Displayed on Channel B 20
5.5 Changing the Air Handler Flow Units 20
5.6 Changing the Time Averaging Period for the Step 2 Procedure 20
5.7 Test Procedure For Measuring Air Handler Flow 20
5.7.a Step 1: Measuring the NSOP 20
5.7.b Step 2: Measuring the TFSOP and Adjusted Air Handler Flow 21
5.8 Flow Resistance Correction Factors Used in the DG-700 22
CHAPTER 6 PRESSURE/VELOCITY MODE 23
6.1 Mode Summary 23
6.2 Overview of Pressure/Velocity Mode 23
6.3 Changing the Air Velocity Units 23
6.4 Changing the Time Averaging Period 23
6.5 Air Velocity Calculations Used in the DG-700 23
CHAPTER 7 SERVICING AND MAINTENANCE 24
7.1 Gauge Calibration and Servicing 24
7.1.a Calibration: 24
7.1.b Servicing/Repairs: 24
7.2 Low Battery Indicator/Battery Replacement 24
7.2.a Low Battery Indicators: 24
7.2.b Battery Replacement: 24
7.3 Troubleshooting/Resetting the DG-700 25

7.4 AC Power Supply Specifications 25
APPENDIX A QUICK GUIDES FOR USING THE DG-700 WITH ENERGY
CONSERVATORY TEST DEVICES 26
A.1 One-Point 50 Pascal Building Depressurization Test using the Model 3 Minneapolis Blower Door™
and DG-700 Digital Gauge 26
A.2 One-Point 25 Pascal Total Leakage Duct Pressurization Test Using the Seried B Minneapolis Duct
Blaster

and DG-700 Digital Gauge 28
A.3 Using the TrueFlow

Air Handler Flow Meter and the DG-700 Digital Gauge 30
A.4 DG-700 Connections Needed to Conduct Automated Blower Door Tests 32
A.5 Using the DG-700's Cruise Control Feature 36

Chapter 1 Feature Summary
Chapter 1 Feature Summary
The DG-700 Pressure and Flow Gauge is a multi-functional differential pressure gauge with 2 independent
measurement channels. In addition to providing high resolution pressure measurements, the DG-700 is programmed
to operate with other Energy Conservatory test devices to provide air flow measurements during building
performance test procedures. The DG-700’s dual pressure channels and air flow measurement features make it
ideally suited for a wide range of building performance testing applications including:
Blower Door airtightness testing.
Duct system airtightness testing.
Air handler flow measurements.
Exhaust fan flow measurements.
Building depressurization and combustion safety testing.
1.1 Feature List
1.1.a Pressure Measurements:
-Simultaneous display of 2 independent differential pressure channels (Aand B).
-Each pressure channel has a range of –1,250 Pascals to +1,250 Pascals.
-Accuracy of pressure channels is +/- 1% of reading, or 2 times the resolution, whichever is greater.
-Auto ranging with 0.1 Pascal resolution.
-Choice of pressure units (Pascals or Inches w.c.).
-Specialized “Baseline” feature on Channel A allows user to measure and record a baseline pressure reading,
and then display the baseline adjusted pressure reading.
1.1.b Auto Zeroing:
-Auto-zeroing feature for both measurement channels automatically adjusts for sensitivity to position and
operating temperature during operation (automatically activated every 10 seconds).
1.1.c Time Averaging:
-Choice of 4 time-averaging options (1 second, 5 second, 10 second and Long-Term average). The time-
averaging feature stabilizes readings when measuring fluctuating signals (e.g. windy conditions).
1.1.d Air Flow and Velocity Measurements:
-The DG-700 will calculate and display air flow readings on Channel B for the following Energy Conservatory
test devices: (choice of units - cubic feet per minute (CFM), meters3 per hour (m3/hr), liters per second (l/s))
Model 3 Minneapolis Blower Door™ fans (110V and 220V).
Model 4 Minneapolis Blower Door fans (220V).
Series A and B Minneapolis Duct Blaster® fans.
Exhaust Fan Flow Meter.
TrueFlow® Air Handler Flow Meter.
-The DG-700 will calculate and display air velocity readings on Channel B from a standard pitot tube. (choice of
units – feet per minute (FPM), meters per second (m/s))
1.1.e Display “HOLD”:
When the “HOLD” button is pushed, the DG-700 display is temporarily frozen with the most recent readings and
settings. The Hold feature is turned off by pushing the “HOLD” button a second time.
1 Operating Instructions
for the DG700

Chapter 1 Feature Summary
1.1.f Specialized @ 50 and @ 25 Leakage Measurement Mode:
-For one-point airtightness tests of building and duct systems, the DG-700 will display on Channel B estimated
leakage rates adjusted to either 50 Pascals or 25 Pascals of test pressure.
-Choice of leakage units (CFM @, m3/hr @, l/s @, sq. inches @ , sq. centimeters @).
1.1.g Specialized Air Handler Flow Measurement Mode:
-Designed for measuring air handler flow rates using a TrueFlow Air Handler Flow Meter or a Duct Blaster fan.
-Automatically adjusts displayed air flow rate using measured system operating pressures (NSOP and TFSOP).
-Choice of air flow units (cfm, m3/hr, l/s).
1.1.h Automated Blower Door Testing, Cruise Control and Data Logging:
-The DG-700 can be used along with a computer and specialized TEC software (TECTITE, TECTITE Express
or TECLOG2) to conduct fully automated Blower Door tests.
-The Cruise Control feature allows you to automatically control a Blower Door or Duct Blaster fan to maintain a
constant 75Pa, 50 Pa, 25 Pa or 0 Pa building pressure without having the gauge connected to a computer.
-Both of the DG-700’s pressure channel readings can be recorded using TEC’s TECLOG2 data logging software.
1.2 Overview of Gauge Operating Modes
Mode
Application
Channel A Display
Channel B Display
Pressure/Pressure
(PR/ PR)
Multi-purpose pressure
measurements.
Pressure in units chosen
(Pa, in w.c.).
Pressure in units chosen
(Pa, in w.c.).
Pressure/Flow
(PR/ FL)
Multi-purpose pressure
and air flow
measurements.
Pressure in Pascals.
Nominal (unadjusted) air flow from the
selected Energy Conservatory test
device, in units chosen (CFM, m
3
/h, l/s).
Pressure/Flow @ 50 Pa
(PR/ FL@50)
Specialized mode for
one-point Blower Door
building airtightness
test.
Building pressure in Pascals.
Building leakage at 50 Pascals in units
chosen (CFM@50, m3/h@50, l/s@50,
in2@50, cm2@50). Leakage rate is
determined by continuously adjusting
the measured air flow from the selected
Blower Door fan to a building pressure
of 50 Pascals, using the real-time
Channel A building pressure reading.
Pressure/Flow @ 25 Pa
(PR/ FL @25)
Specialized mode for
one-point total leakage
duct airtightness test.
Duct system pressure in
Pascals.
Total duct leakage at 25 Pa in units
chosen (CFM@25, m3/h@25, l/s@25,
in2@25, cm2@25). Leakage rate is
determined by continuously adjusting
the measured air flow from the selected
duct testing fan to a duct pressure of 25
Pascals, using the real-time Channel A
duct pressure reading.
Pressure/AH Flow
(PR/ AH)
Specialized mode for
measuring air handler
flow rates using a
TrueFlow Air Handler
Flow Meter or a Duct
Blaster fan.
Normal system operating
pressure (NSOP) and test
flow system operating
pressure (TFSOP) in Pascals.
Total air handler flow in units chosen
(CFM, m3/h, l/s). Air flow from the
selected Energy Conservatory test
device is continuously adjusted using
the measured NSOP and TFSOP
readings from Channel A.
Pressure/Velocity
(PR/ V)
Pressure and air
velocity measurements.
Pressure in Pascals.
Air velocity in units chosen
(FPM, m/s).
2 Operating Instructions
for the DG700

Chapter 1 Feature Summary
1.3 Gauge Face and Buttons
Button
Purpose
Button
Purpose
DEVICE
Used to select the Energy Conservatory test device
connected to Channel B (not active in PR/PR
mode).
BASELINE
Initiates Baseline pressure measurement procedure
on Channel A (not active in PR/AH mode).
UNITS
Selects the pressure and air flow units for Channels
Aand B.
START
Used to start measurement procedure for Baseline
and NSOP measurements. Also used to reset time
averaging buffers and manually initiate auto-zero.
CONFIG
Used to select the configuration for the currently
chosen test device (not active in PR/PR mode).
ENTER
Used to accept and enter Baseline and NSOP
pressure readings. After entering Baseline reading,
Channel A will display baseline adjusted pressure.
MODE
Selects the current operating mode.
ON/OFF
Turns gauge On and Off.
CLEAR
Used to exit out of a Baseline pressure
measurement procedure. When in PR/AH mode,
resets gauge back to beginning of AH flow
measurement procedure (i.e. NSOP measurement).
Also used to turn off the Cruise Control feature.
LIGHT
Turns display backlight On and Off.
TIME AVG
Used to select the time averaging mode (not active
during Baseline and NSOP measurements).
HOLD
Turns display Hold feature On and Off.
Begin Cruise
Initiates Cruise Control feature (not active in
PR/AH and PR/V modes).
Stop Fan
Turns off the fan for Cruise Control.
Start Fan
Starts the fan for Cruise Control.
Cruise Target
Used to select the Cruise Target Pressure.
Channel A Reading
Channel B Reading
Selected test device
configuration (for air flow
measurements on Channel B)
Selected test device (for air
flow measurements on
Channel B)
Selected Operating Mode
Selected Time Averaging
(for both Channels)
Display Hold Indicator
Low Battery Indicator
Channel A Input Tap
Channel A Reference Tap
Channel B Input Tap
Channel B Reference Tap
3 Operating Instructions
for the DG700

Chapter 1 Feature Summary
1.4 Input/Output Ports on the DG-700
1.4.a USB and Serial Communication Ports:
The DG-700 contains both a USB and a DB-9 serial communication port, either of which can be used to create a 2-
way communication link between the gauge and a computer. This communication link can be used (along with TEC
software) to conduct automated Blower Door tests and to data log both pressure channels.
-Automated Blower Door testing requires the TECTITE, TECTITE Express or TECLOG2 software, a Blower
Door fan speed controller with a communication jack (standard equipment since September 2004), a fan control
cable, and a communication cable (either USB or 9 pin serial) to connect the DG-700 to a user supplied laptop
computer.
-Data logging of pressure measurements requires the TECLOG2 software (available from
www.energyconservatory.com), and a communication cable (either USB or 9 pin serial) to connect the DG-700
to a user supplied laptop computer.
1.4.b Fan Control Output Jack:
The fan control output jack provides a speed control signal which is used to control a Blower Door or Duct Blaster
fan during an automated Blower Door test, or with the Cruise Control feature. A fan control cable is used to connect
the fan control output jack to the communication jack on the side of the fan speed controller.
1.4.c AC Power Input Jack:
The AC power input jack can be used with an optional AC power supply to provide a long term power source for the
gauge (to be used when data logging). The gauge is normally powered by 6 AA batteries located in the rear battery
compartment. When the AC power supply is plugged in, the power supply bypasses the batteries in the battery
compartment. See Chapter 7 for AC power supply specifications. Note:Always turn off the gauge before plugging
in the AC power supply.
AC Power Input Jack
Serial
Communication
Port
Fan Control
Output Jack
USB
Communication
Port
Communication Jacks
(Blower Door and
Duct Blaster Speed
Controllers)
4 Operating Instructions
for the DG700

Chapter 1 Feature Summary
1.5 Overview of the Time Averaging Feature
The DG-700 has a choice of 4 time averaging periods which are applied to both measurement channels.
When the gauge is turned on, the default time averaging period is 1 second average. To change the
selected time averaging period, press the TIME AVG button. The currently selected time averaging
period is shown in the TIME AVG portion of the gauge display.
1.5.a Description of Time Averaging Periods:
-1 Second Average (1)– Both measurement channels are updated once per second with the average of the
readings from the previous 1 second. The 1 Second Average is the default time averaging period when turning
on the gauge, and is the period most commonly used.
-5 Second Average (5)– Both measurement channels are updated once every 5 seconds with the average of the
readings from the previous 5 second period. When first activated, the display shows "---" until the first 5 second
measurement buffer has been recorded. The 5 Second Average should be used when the 1 Second Average
reading is fluctuating more than desired.
-10 Second Average (10)– Both measurement channels are updated once every 10 seconds with the average of
the readings from the previous 10 second period. When first activated, the display will show
"---" until the first 10 second measurement buffer has been recorded. The 10 Second Average mode should be
used when the 5 Second Average reading is fluctuating more than desired.
-Long Term Average (L)– Both measurement channels are updated once per second with the running average of
all readings taken after the Long Term Average period is activated. When using Long Term Average, the gauge
continuously adds the current measurements to the measurement buffer and displays the average value of all
recorded measurements. The gauge will operate for approximately 2 hours when using Long Term Average
before the measurement buffer is overloaded. When the buffer is overloaded, both channel readings will re-start
a new long-term average period.
1.5.b Illustration of Time-Averaging Operation (First 10 seconds of operation):
1 Second Average:
Seconds: 1 2 3 4 5 6 7 8 9 10
Pressure 12 5 10 2 6 15 8 12 2 6
Signal:
Display: 12 5 10 2 6 15 8 12 2 6
5 Second Average:
Seconds: 1 2 3 4 5 6 7 8 9 10
Pressure 12 5 10 2 6 15 8 12 2 6
Signal:
Display: -- -- -- -- 7 7 7 7 7 9
10 Second Average:
Seconds: 1 2 3 4 5 6 7 8 9 10
Pressure 12 5 10 2 6 15 8 12 2 6
Signal:
Display: -- -- -- -- -- -- -- -- -- 8
Long Term Average:
Seconds: 1 2 3 4 5 6 7 8 9 10
Pressure 12 5 10 2 6 15 8 12 2 6
Signal:
Display: 12 9 9 7 7 8 8 9 8 8
1.5.c Resetting the Time Averaging Measurement Buffer:
When using the 5 second, 10 second or Long Term averages, it is sometimes desirable to reset and
restart the time averaging measurement buffer when an unwanted signal has been recorded during a time
averaging period (e.g. someone steps on the tubing during a Long Term Average measurement). To reset
and restart the time averaging measurement buffer for both channels, press the START button.
5 Operating Instructions
for the DG700

Chapter 1 Feature Summary
1.6 Overview of the Baseline Pressure Measurement Feature (Channel A)
The Baseline feature on Channel A allows the user to measure and record a baseline pressure reading, and then
display the baseline adjusted pressure on the gauge. For purposes of this manual a baseline pressure reading is
defined as a pressure measurement made under a specific operating condition, which will be used to determine the
change in pressure created by a change in the operating condition.
A common building performance application requiring use of a baseline pressure reading is determining the extent of
building depressurization caused by turning on an exhaust fan. In order to accurately quantify the building
depressurization, the user first needs to know the building pressure (with reference to outside) prior to the exhaust
fan being turned on. This initial pressure reading, known as the baseline building pressure, can be quickly measured
and then used to adjust the final building pressure reading (after the exhaust fan is turned on) to determine the actual
change in building pressure caused by fan operation. In the example below, the building depressurization measured
from the exhaust fan operating is –4.2 Pascals (i.e. the building pressure changed from –2.6 Pa to –6.8 Pa when the
exhaust fan was turned on).
1.6.a Buttons Used with Baseline Pressure Feature:
Pressing the BASELINE button initiates the baseline
pressure measurement feature. The word
“BASELINE” will begin to flash in the Channel A
display, indicating that the baseline feature is active. At this
point, the gauge is monitoring the real-time Channel A pressure
reading, but is not recording the reading. The Channel B display
is not active at this time.
Press the START button to begin recording a
baseline pressure reading. Once the START button
is pressed, the word “BASELINE” stops flashing and
the gauge begins recording a long term average baseline
pressure reading on Channel A. During the baseline
measurement procedure, the Channel B display is used as a
timer to let the user know how long (in seconds) the baseline
measurement has been active. The longer the measurement time, generally the more stable the baseline reading
typically becomes.
-1
-2
-3
-4
-5
-6
0
Baseline
Building
Pressure
(Fan Off)
Building
Pressure
(Fan On)
-7
Baseline
Adjusted
Building
Pressure
(Change from
Turning Fan On)
-2.6
-6.8
-4.2
Change in Building
Pressure From
Turning On an
Exhaust Fan (Pa)
6 Operating Instructions
for the DG700

Chapter 1 Feature Summary
Once you are satisfied with the baseline pressure
reading, press the ENTER key to accept and enter
the baseline pressure reading into the gauge. After
pressing ENTER, Channel A will now display the baseline
adjusted pressure reading (i.e. the measured baseline pressure
reading will be subtracted from the current Channel A pressure
measurement). The icon “ADJ” appears in the Channel A display to indicate that the baseline adjusted pressure
reading is displayed. The time averaging period for the gauge reverts back to whatever period was selected prior to
pressing the BASELINE button. In addition, Channel B also reverts back to displaying an unadjusted pressure
reading.
Now create a change in the operating condition of the building
(e.g. turn on and exhaust fan). Channel A will display the
change in building pressure caused by the change in operating
condition.
1.6.b Restarting the Baseline Measurement:
During a baseline measurement procedure (i.e. while the gauge is recording the long term average
baseline pressure), the baseline measurement procedure can be restarted by pressing the START button.
When START is pressed, the measurement buffer and time counter for the baseline reading is cleared
and a new baseline reading is immediately started.
Once a baseline measurement has been taken and entered into the gauge (i.e. ADJ appears below the
Channel A reading), a new baseline measurement procedure can be initiated by pressing the
BASELINE button.
1.6.c Clearing and Exiting from the Baseline Pressure Procedure:
Pressing the CLEAR button clears the baseline measurement buffer and turns the baseline feature off.
The gauge will remain in the operating mode selected prior to the BASELINE button being pressed.
Note: If the gauge Mode is changed while the baseline measurement feature is active, the baseline measurement
buffer is cleared and the baseline feature is turned off.
1.7 Auto-Off Feature
In order to preserve battery life, the DG-700 gauge will automatically shut off if no keys are pressed for 2 hours. The
auto-off feature can be disabled by simultaneously pressing the CLEAR and ENTER buttons. The auto-off feature
is automatically re-enabled whenever the gauge is turned off and then back on.
7 Operating Instructions
for the DG700

Chapter 2 Pressure/Pressure Mode
Chapter 2 Pressure/Pressure Mode
2.1 Mode Summary
Mode
Application
Channel A Display
Channel B Display
Pressure/Pressure
(PR/PR)
Multi-purpose
pressure
measurements.
Pressure in units chosen
(Pa, in w.c.).
Pressure in units chosen
(Pa, in w.c.).
2.2 Overview of Pressure/Pressure Mode
The DG-700 gauge is turned on by pressing the
ON/OFF button once. When first turned on, the gauge
is automatically placed in the Pressure/Pressure
(PR/PR) operating mode and immediately begins monitoring and
displaying pressure readings for both Channels A and B. The
default pressure units for both channels is Pascals, and the default
time averaging period is 1 second average.
Each channel on the DG-700 measures the pressure difference between either of the top Input pressure taps and its
corresponding bottom Reference pressure tap. The gauge can monitor and display both positive and negative
pressure readings (i.e. bi-directional). In order to display the correct "sign" of the pressure reading (i.e. positive or
negative), it is important that the pressure taps are used consistently and logically. The top Input taps should always
be connected to the pressure signal(s) you are trying to measure. The bottom Reference taps should always be
connected to the reference pressure(s) you are measuring the pressure signal with reference to.
For example, let's set up the gauge to measure the pressure in a house with reference to outside using Channel A. If
you are standing in the house, connect tubing to the Channel A Reference tap and run it outside, while leaving the
Channel A Input tap open to the house. The gauge will now display the pressure difference between the house and
outside, along with the correct sign of the reading. If the house is at a lower pressure than outside (e.g. from an
exhaust fan running), then the pressure reading displayed on the gauge will have a minus sign "-" in front of the
reading.
On the other hand, if you are standing outside and wish to make the same reading, connect a piece of tubing to the
Channel A Input tap and run it into the house, while leaving the Channel A Reference tap open to the outside. The
gauge will now display the same house to outside pressure difference as above, along with the correct sign. Note: In
either case, if you had connected the tubing to the wrong tap on Channel A, the display would show the correct
differential pressure reading, however, the reading would have the wrong sign.
2.3 Changing the Pressure Units
When in the PR/PR operating mode, the DG-700 can display pressure readings in units of Pascals or
inches w.c.. The default pressure units for the gauge is Pascals for both Channels A and B. To change
the pressure units for both channels, press the UNITS button. The selected pressure units are shown on
the gauge display directly below each of the channel readings.
8 Operating Instructions
for the DG700

Chapter 2 Pressure/Pressure Mode
2.4 Changing the Time Averaging Period
The DG-700 has a choice of 4 time averaging periods which are applied to both pressure measurement
channels. The default time averaging period is 1 second average. To change the selected time averaging
period, press the TIME AVG button. The selected time averaging period is shown in the TIME AVG
portion of the gauge display. (See Section 1.5 for an overview of the time averaging feature).
2.5 Using the Baseline Pressure Feature
The Baseline feature on Channel A allows the user to measure and record a
baseline pressure reading, and then display the baseline adjusted pressure reading.
(See Section 1.6 for an overview of the baseline pressure feature)
2.5.a Example: Measuring Building Depressurization from an Exhaust Fan
A common building performance application requiring use of a baseline pressure reading is determining the extent of
building depressurization caused by turning on an exhaust fan. In order to accurately quantify the building
depressurization, the user first needs to know the building pressure (with reference to outside) prior to the exhaust
fan being turned on. This initial pressure reading, known as the baseline building pressure, can be quickly measured
and then used to adjust the final building pressure reading (after the exhaust fan is turned on) to determine the actual
change in building pressure caused by fan operation.
-Set up Channel A to measure building pressure with reference to outside (e.g. run tubing from the Channel A
Reference tap to outside and leave the Channel A Input tap open to the building – assumes the gauge is in the
building).
-With the exhaust fan off, turn on the gauge and leave it in the PR/PR mode.
-Press the BASELINE button. The word “BASELINE” will
begin to flash in the Channel A display, indicating that the
baseline feature has been initiated. At this point, the gauge is
monitoring the real-time Channel A baseline pressure
reading, but is not recording the reading. The Channel B
display is not active at this time.
-Press the START button to begin the baseline measurement
procedure on Channel A. Once the START button is
pressed, the word “BASELINE” stops flashing and the
gauge begins recording a long term average baseline
pressure reading on Channel A. During the baseline
measurement procedure, the Channel B display is used as a
timer to let the user know how long (in seconds) the baseline measurement has been active. The longer the
measurement time, generally the more stable the baseline reading typically becomes. In the screen to the right,
the measured baseline pressure is –2.6 Pascals (measured over the past 45 seconds).
-Once you are satisfied with the baseline pressure reading,
press the ENTER key to accept and enter the baseline
pressure reading into the gauge. After pressing ENTER,
Channel A will now display the baseline adjusted pressure
reading (i.e. the measured baseline pressure reading will be
9 Operating Instructions
for the DG700

Chapter 2 Pressure/Pressure Mode
subtracted from the current Channel A pressure measurement). The icon “ADJ” appears in the Channel A
display to indicate that the baseline adjusted pressure reading is displayed. The time averaging period for the
gauge reverts back to whatever period was selected prior to pressing the BASELINE button. Note: At this
point, Channel B also reverts back to displaying an unadjusted pressure reading.
-Turn on the exhaust fan. Channel A will now display the
actual change in building pressure created by the exhaust
fan. In the screen to the right, the building depressurization
measured from the exhaust fan operating is –4.2 Pascals
(i.e. the building pressure changed from –2.6 Pa to –6.8
Pa when the exhaust fan was turned on).
-While displaying the baseline adjusted pressure on Channel A, the user can change the selected time averaging
period if the pressure reading is fluctuating more than desired.
-Channel B can be used to simultaneously measure any other unadjusted pressure signal, such as the flue
pressure in a combustion appliance.
Note: Pressing the CLEAR button clears the baseline measurement buffer and turns the baseline feature off. If the
gauge Mode is changed while the baseline measurement feature is active, the baseline measurement buffer is cleared
and the baseline feature is turned off.
10 Operating Instructions
for the DG700

Chapter 3 Pressure/Flow Mode
Chapter 3 Pressure/Flow Mode
3.1 Mode Summary
Mode
Application
Channel A Display
Channel B Display
Pressure/Flow
(PR/ FL)
Multi-purpose
pressure and air flow
measurements.
Pressure in Pascals.
Nominal (unadjusted) air flow from the
selected Energy Conservatory test
device, in units chosen (CFM, m
3
/h, l/s).
3.2 Overview of Pressure/Flow Mode
The Pressure/Flow mode is a multi-purpose mode used to
measure a test pressure on Channel A while simultaneously
measuring air flow from an Energy Conservatory test device on
Channel B. The Pressure/Flow mode a very versatile operating
mode and is typically used whenever simultaneous pressure and
air flow measurements are needed (except when using the
specialized PR/ FL@50, PR/ FL@25 and PR/ AH modes).
To select the Pressure/Flow mode, press the MODE button until the selected operating mode shown on
the gauge display is PR/ FL. When first entering this mode, the default pressure units on Channel A is
Pascals, the default air flow units on Channel B is CFM (cubic feet per minute), and the default selected
test device is the Model 3 (110V) Minneapolis Blower Door. The default time averaging period is 1 second average.
3.3 Changing the Selected Test Device and Configuration
The DG-700 can display air flow from the following Energy Conservatory test devices on
Channel B:
Model 3 (110V) Minneapolis Blower Door™ fans (BD 3).
Model 3 (220V) Minneapolis Blower Door™ fans (BD 3 220).
Model 4 (220V) Minneapolis Blower Door fans (BD 4).
Series A Minneapolis Duct Blaster® fans (DB A).
Series B Minneapolis Duct Blaster® fans (DB B).
Exhaust Fan Flow Meter (EXH).
TrueFlow® Air Handler Flow Meter (TF).
Press the DEVICE button to toggle through the available test devices. The currently selected test device is shown in
the Device section of the gauge display. The Model 3 (110V) Minneapolis Blower Door is the default test device
when first entering the PR/ FL mode.
Once a test device is selected, the configuration of the device (i.e. flow rings, door position or plate installed) can be
selected by pressing the CONFIG button. The currently selected device configuration is shown in the Config section
of the gauge display.
11 Operating Instructions
for the DG700

Chapter 3 Pressure/Flow Mode
3.4 “LO” Displayed on Channel B
Whenever “LO” appears on Channel B in the PR/ FL mode, the pressure signal from the test device is too low to
provide a reliable air flow reading. The message “LO” appears on the Channel B display under the following two
conditions:
“LO” is continuously displayed on Channel B when there is negligible air flow through the test device.
“LO” alternates with a flow reading when the air flow reading through the device is unreliable (i.e. you are
trying to measure a flow outside of the calibrated range of the test device in its current configuration). If
possible, the user should change the test device configuration to match the flow rate being measured (e.g. install
a flow ring or a smaller flow ring).
3.5 Changing the Air Flow Units
When in the PR/ FL operating mode, the DG-700 can display air flow readings on Channel B in units of
CFM,m3/hr, or l/s. The default air flow unit is CFM. To change the air flow unit for Channel B, press
the UNITS button. The selected air flow units are shown on the gauge display directly below the
Channel B readings. The pressure unit for Channel A is always Pascals when in the PR/ FL mode.
3.6 Changing the Time Averaging Period
To change the selected time averaging period for both Channel A and B, press the TIME AVG button.
The selected time averaging period is shown in the TIME AVG portion of the gauge display. (See
Section 1.5 above for a complete description of the time averaging periods.)
3.7 Using the Baseline Pressure Feature in Pressure/Flow Mode
The Baseline feature on Channel A allows the user to measure and record a
baseline pressure reading, and then display the baseline adjusted pressure reading.
This feature is commonly used during both building and duct airtightness test
procedures where the user wishes to display the actual change in building or duct pressure caused by operation of the
Blower Door or duct airtightness testing fan. In order to accurately determine the change in pressure from the test
fan, the user first needs to know the building or duct system pressure (with reference to outside) prior to the test fan
being turned on. This initial baseline pressure reading can be quickly measured and then used to adjust the test
pressure readings to determine the actual change in pressure caused by operation of the Blower Door or duct
airtightness test fan. (See Section 1.6 for an overview of the baseline pressure feature)
3.7.a Example: Using the Baseline Feature During a Blower Door Depressurization Test
-Set up Channel A to measure building pressure with reference to outside (e.g. run tubing from the Channel A
Reference tap to outside and leave the Channel A Input tap open to the building – assumes the gauge is in the
building). Run tubing from the Channel B Input tap to the pressure tap on the Blower Door fan.
-With the Blower Door off and the No-Flow Plate installed, turn on the gauge and put it the PR/ FL mode by
pressing the MODE button.
-Select the Blower Door fan device you will be using by pressing the DEVICE button (Model 3 fan is the default
test device when entering the PR/ FL mode).
12 Operating Instructions
for the DG700

Chapter 3 Pressure/Flow Mode
-Press the BASELINE button. The word “BASELINE” will
begin to flash in the Channel A display, indicating that the
baseline feature has been initiated. At this point, the gauge is
monitoring the real-time Channel A baseline building
pressure (i.e. the existing building pressure caused by stack
and wind effects), but is not recording the reading. The
Channel B display is not active at this time.
-Press the START button to begin the baseline measurement
procedure on Channel A. Once the START button is
pressed, the word “BASELINE” stops flashing and the
gauge begins recording a long term average baseline
building pressure reading on Channel A. During the
baseline measurement procedure, the Channel B display is
used as a timer to let the user know how long (in seconds) the baseline measurement has been active. The longer
the measurement time, generally the more stable the baseline reading typically becomes. In the screen to the
right, the measured baseline building pressure is –3.8 Pascals (measured over the past 60 seconds).
-Once you are satisfied with the baseline pressure reading,
press the ENTER key to accept and enter the baseline
pressure reading into the gauge. After pressing ENTER,
Channel A will now display the baseline adjusted building
pressure reading (i.e. the measured baseline pressure
reading will be subtracted from the current Channel A
pressure measurement). The icon “ADJ” appears in the Channel A display to indicate that the baseline adjusted
pressure reading is displayed. The time averaging period for the gauge reverts back to whatever period was
selected prior to pressing the BASELINE button. Channel B is now set up to display the air flow through the
Blower Door fan (it will read LO until the fan is turned on).
Note: With the Blower Door fan off and the No-Flow Plate installed, the baseline adjusted building pressure on
Channel A should be reading close to zero. However if it is windy, there may be fluctuations either side of 0.
-Install the appropriate flow ring and turn on the Blower
Door fan. Channel A will now display the baseline adjusted
building pressure while Channel B displays the flow
through the Blower Door fan. In the screen to the right, the
DG-700 is measuring an actual building depressurization –
48.6 Pascals caused by the 3,564 CFM of air flow through
the Blower Door fan (open fan).
-If the readings are fluctuating more than desired, change the time averaging period to 5 second average, 10
second average or long term average.
-Record the building pressure and fan flow readings at the various target building pressures used in your test
procedure.
3.7.b Entering Baseline Readings into TECTITE Software When Using the Baseline Feature:
-When using the Baseline feature, and the TECTITE program to analyze your test data, be sure to enter “0” into
the Pre and Post Test Baseline fields in the Manual Data Entry Table. This is because the Baseline feature
automatically subtracts the measured baseline pressure from the building test pressure readings.
Note: Pressing the CLEAR button clears the baseline measurement buffer and turns the baseline feature off. If the
gauge Mode is changed while the baseline measurement feature is active, the baseline measurement buffer is cleared
and the baseline feature is turned off.
13 Operating Instructions
for the DG700