Shortridge Instruments AIRDATA ADM-880C User manual

ADM-880C 07/20/09
Shortridge Instruments, Inc.
7855 East Redfield Road / Scottsdale, Arizona 85260-3430
Phone [phone] • Fax [phone]
www.shortridge.com
S
i®
AIRDATA™MULTIMETER ADM-880C
ELECTRONIC MICROMANOMETER
WITH 2000 READING MEMORY, DATALOGGING
CAPABILITY AND RS232 COMMUNICATIONS PORT
• AIR FLOW • VELOCITY • PRESSURE • TEMPERATURE •
OPERATING INSTRUCTIONS

ADM-880C 07/20/09i
CONTENTS
1.0 INTRODUCTION 1
2.0 SPECIFICATIONS 2
3.0 EXTERNAL FEATURES 4
3.1 KEYPAD LAYOUT 5
3.3 FEATURES ON SIDES AND BACK OF METER 6
4.0 DISPLAY MESSAGES AND PROMPTS 7
4.1 READ PROMPTS 7
4.2 MEASUREMENT READOUTS 7
4.3 FUNCTION READOUTS 8
5.0 USING THE ADM-880C AIRDATA MULTIMETER 18
5.1 KEYPAD 18
5.1.1 KEYPAD LAYOUT 18
5.1.2 KEYPAD FUNCTIONS 18
5.1.3 NUMERICAL ENTRY 19
5.1.4 GENERAL USE 19
5.2 ALT KEY 20
5.2.1 ALTERNATE FUNCTION 20
5.2.2 ESCAPE 20
5.2.3 VIEW BATTERY LEVEL AND METER SETTINGS 20
5.3 ON/OFF KEY 20
5.3.1 ON AND OFF 20
5.3.2 BACKLIGHT 20
5.4 =SCAN KEY 20
5.4.1 SCROLL THROUGH MEMORY - DESCENDING 20
5.4.2 “GO TO” A READING 21
5.5 SCAN<KEY 21
5.5.1 SCROLL THROUGH MEMORY - ASCENDING 21
5.5.2 RESET DISPLAY 21
5.6 READ/SELECT KEY 21
5.6.1 MANUAL READINGS 21
5.6.2 AUTOMATIC READINGS 22
5.6.3 TREND READINGS 22
5.6.4 SELECT 22
5.7 STORE KEY 22
5.7.1 STORE MODE 22
5.7.1.1 STORE ALL 23
5.7.1.2 STORE LAST 23
5.7.1.3 STORE OFF 23
5.7.2 CLEAR MEMORY 23
5.7.3 CHANGE MEMORY 23
5.7.3.1 CHANGE MEMORY GROUP 24
5.7.3.2 REPLACE READING IN MEMORY 24
5.7.3.3 ERASE READING IN MEMORY 24
5.8 VIEW KEY 24
5.8.1 VIEW GROUP STATISTICS 24
5.8.2 VIEW ASSOCIATED DATA 25
5.8.3 DOWNLOAD TO PRINTER 25
5.9 MODE KEY 26
5.9.1 MEASUREMENT MODE 26
5.9.2 TIMED READING MODE 26
5.9.3 CONFIGURATION SETTINGS 27
5.9.3.1 CONFIGURE UNITS 27
5.9.3.2 CONFIGURE DENSITY 27
5.9.3.3 CONFIGURE TIME 27
5.9.3.4 CONFIGURE DATE 28
5.10 RS232 DOWNLOAD USING ADM DATAFLOW SOFTWARE 28
5.10.1 QUALIFIED OPERATING SYSTEMS 28

ADM-880C 07/20/09ii
5.10.2 INSTALLING DATAFLOW SOFTWARE 28
5.10.3 USING DATAFLOW SOFTWARE 28
5.10.4 IMPORTING SAVED DATA INTO A SPREADSHEET 29
5.11 BATTERY DISPLAY AND BATTERY LIFE 29
5.12 RESET SWITCH 29
6.0 VELOCITY MEASUREMENT 31
6.1 VELOCITY CORRECTION FACTORS 31
6.2 PITOT TUBE VELOCITY MEASUREMENT 32
6.3 AIRFOIL PROBE VELOCITY MEASUREMENT 33
6.3.1 DUCT VELOCITY USING AIRFOIL PROBE 34
6.3.2 FUME HOODS AND SAFETY CABINETS 34
6.3.3 EXHAUST HOODS - AIRFOIL PROBE 34
6.3.4 LAMINAR FLOW WORKSTATIONS - AIRFOIL PROBE 35
6.4 SINGLE POINT CENTERLINE AIR VELOCITY MEASUREMENTS 35
6.5 VELGRID AIR VELOCITY 35
6.5.1 CHEMICAL EXHAUST HOODS - VELGRID 36
6.5.2 LAMINAR FLOW WORKSTATION - VELGRID 36
6.5.3 AIR FLOW CALCULATION FROM VELGRID VELOCITY 36
6.6 VELOCITY: LOCAL DENSITY VERSUS STANDARD DENSITY 36
7.0 PRESSURE MEASUREMENT 38
7.1 DIFFERENTIAL PRESSURE 38
7.1.1 STATIC PRESSURE PROBES 38
7.1.2 PITOT TUBE "VELOCITY PRESSURES" 38
7.1.3 PITOT TUBE "STATIC PRESSURES" 38
7.1.4 PITOT TUBE "TOTAL PRESSURES" 39
7.2 ABSOLUTE PRESSURE 39
8.0 TEMPERATURE MEASUREMENT 40
8.1 TEMPROBE 40
8.2 AIRDATA MULTITEMP 40
9.0 AIR FLOW MEASUREMENT 42
9.1 FLOWHOOD FUNCTION 42
9.2 BACKPRESSURE COMPENSATION 42
10.0 FLOWHOOD ASSEMBLY 43
10.1 UNPACKING 43
10.2 FRAME ASSEMBLIES 43
10.3 FABRIC TOPS 43
10.4 TOP SUPPORT ASSEMBLY 43
10.5 HANDLE 44
11.0 FLOWHOOD OPERATING PROCEDURE 49
11.1 AIR FLOW - NONBACKPRESSURE COMPENSATED READINGS 49
11.2 AIR FLOW - BACKPRESSURE COMPENSATED READINGS 49
11.2.1 MEMORY DISPLAY IN FLOWHOOD MODE 50
11.2.2 RATIO ERR DISPLAY 50
12.0 SPECIAL BALANCING PROCEDURES 51
12.1 PROPORTIONAL BALANCING 51
12.2 LARGE RETURN AIR GRILLES 51
12.3 KITCHEN EXHAUST HOODS 51
12.3.1 RANGE EXHAUST FILTERS AND GREASE EXTRACTORS 51
12.4 CONSTANT VOLUME CONTROLLERS 51
12.5 LINEAR SLOT DIFFUSERS 52
12.6 SIDEWALL REGISTERS 52
12.7 14"x14"x14" SHORT TOP SET 52
12.8 SYSTEM PROBLEMS 52
13.0 CORRECTION FACTORS 53
13.1 BAROMETRIC PRESSURE DENSITY CORRECTION 53

ADM-880C 07/20/09iii
13.2 TEMPERATURE DENSITY CORRECTION 53
13.3 RELATIVE HUMIDITY CORRECTION 53
13.4 HOT WIRE ANEMOMETER VERSUS AIRDATA MULTIMETER 53
14.0 METER ACCURACY FIELD TESTING 55
14.1 METER ZERO FUNCTION 55
14.2 DIFFERENTIAL PRESSURE FUNCTION 55
14.3 ABSOLUTE PRESSURE FUNCTION 55
14.4 AIR FLOW ACCURACY 55
14.5 DUCT TRAVERSE COMPARISON, INCLINED MANOMETER OR MICROMANOMETER 56
14.6 DUCT TRAVERSE USING THE AIRDATA MULTIMETER 56
14.7 BACKPRESSURE COMPENSATED COMPARISON READING 56
14.8 NONBACKPRESSURE COMPENSATED READING 56
15.0 METER MAINTENANCE 57
16.0 FLOWHOOD MAINTENANCE 57
17.0 RECALIBRATION AND REPAIR INFORMATION 58
AIR BALANCE MANUALS & TRAINING PROGRAMS 58
WARRANTY 59
APPENDIX A - NIST VELOCITY TESTING 60
APPENDIX B - LABORATORY DIFFERENTIAL PRESSURE TEST 61
APPENDIX C - BATTERY TEST PROCEDURE 62
REPLACEMENT PARTS LIST 64
INDEX 66
Copyright © Shortridge Instruments, Inc., 2009. All rights reserved. This information may not be reproduced or duplicated in
any manner, or for any purpose, without permission in writing from Shortridge Instruments, Inc. Addendums or revisions
made to this manual after July 2009 may be found at www.shortridge.com.

ADM-880C 07/20/09iv
ILLUSTRATIONS
3.1 ADM-880C METER FRONT AND BACK 4
5.1 ADM-880C AIRDATA MULTIMETER SPREADSHEET EXAMPLE 30
6.1 PITOT TUBE 32
6.2 AIRFOIL PROBE 34
6.3 VELGRID ASSEMBLY 37
7.1 STATIC PRESSURE PROBE 38
8.1 ADT442 TEMPROBE 40
8.2 AIRDATA MULTITEMP 41
10.1 FRAME STORAGE 45
10.2 FLOWHOOD IN CASE 45
10.3 FLOWHOOD ASSEMBLY 46
10.4 2X2 FRAME ASSEMBLY 47
10.5 1X4 FRAME ASSEMBLY 47
10.6 2X4 FRAME ASSEMBLY 47
10.7 1X5 FRAME ASSEMBLY 48
10.8 3X3 FRAME ASSEMBLY 48

ADM-880C 07/20/091
1.0 INTRODUCTION
This meter measures air velocity when used with a Dwyer Series 160 standard pitot tube, AirFoil probe, or VelGrid and
automatically corrects for density variations due to local barometric pressure. The meter also automatically corrects for
density variations due to local temperature if the TemProbe is connected. Velocity ranges are 25-29,000 fpm using a pitot
tube, 25-5,000 fpm using the AirFoil probe, and 25-2500 fpm using the VelGrid. The associated temperature, absolute
pressure, time and date may be viewed for any manual or automatic reading taken with an AirFoil probe or VelGrid in the
velocity mode. The associated differential pressure (velocity pressure) may also be viewed for velocity readings taken using
the pitot tube. Velocity measurements may be displayed in either local air density or the standard density (mass flow) sea
level equivalent. All measurement modes may be displayed in either English or metric units.
When used with the Series 8400 FlowHood System, this unit measures air flow, compensates for the density effects of
barometric pressure and temperature and may also be used to compensate for backpressure effects, allowing direct air flow
readings from 25-2500 cfm. The associated temperature, absolute pressure, time and date may be viewed for any manual
or automatic reading taken in the FlowHood mode. Flow measurements may be displayed in either local air density or the
standard density (mass flow) sea level equivalent.
Differential pressure measurements can be obtained from 0.0001 in wc to 60.00 in wc. Absolute pressure measurements
range from 10-40 in Hg. Temperatures can be measured from -67/F to 250/F, either individually, or in conjunction with
an air flow or velocity measurement.
The Model ADM-880C AirData Multimeter offers additional features which greatly simplify the complex technical
requirements of highly demanding test and balance projects.
This model features an automatic reading mode which registers repeated measurements in any mode, with sequential
storage and recall of up to 2000 automatically or individually stored readings, with sequence tags for each value. Readings
may be stored in up to 25 different memory groups. Recall of the sum, average, standard deviation, time and date for all
readings in each measurement mode in any memory group, along with the minimum and maximum readings for each
measurement mode within the memory group is available at any point, without terminating the process. Readings in either
the current or a previous memory group may be erased or replaced with a new reading along with the new time, date and
associated data. The statistics will be revised to include the revised information.
This meter also features datalogging capabilities. The meter may be programmed with start, stop and interval times to take
and store up to 2000 readings at specified intervals with all of the recall capabilities described above.
The ADM-880C AirData Multimeter includes a custom serial cable with an RS232 connector for use with the RS232 port
on the meter. The kit also includes the Shortridge Instruments, Inc. ADM DataFlow software utility, which may be used to
download readings into a Microsoft Excel® or similar spreadsheet for display, analysis, and manipulation. The DataFlow
software downloads all readings in all measurement modes, along with all related statistics and associated data for each
measurement mode.
This RS232 port and cable may also be used with a compatible portable printer. The contents of all readings stored in
memory can be downloaded and printed as needed.
Internal calibration and zeroing of the AirData Multimeter are fully automatic. No external adjustments are ever needed.
This instrument is extremely tolerant of overpressure, and is unaffected by position or ambient temperatures from 40/F to
140/F. It is recommended that the AirData Multimeter kit be returned to the factory at least every two years for recalibration
and software update. This preventive maintenance program will assure that the original accuracy of the meter is maintained
throughout the life of the meter.

ADM-880C 07/20/092
2.0 SPECIFICATIONS
AIR VELOCITY: Measured in feet per minute (fpm), or meters per second (m/s), corrected for local or standard air density.
The measurement range is 25 to 29,000 fpm with a Dwyer Series 160 standard pitot tube, and 25 to 5,000 fpm with
the Shortridge Instruments, Inc. AirFoil probe. The measurement range using the VelGrid is 25 to 2500 fpm.
Accuracy is ± 3% of reading ± 7 fpm from 50 to 8000 fpm. Pitot tube velocity readings from 8,000 fpm to 29,000 fpm
are based on compressible isentropic flow theory and are not certified NIST traceable.
DIFFERENTIAL PRESSURE: Measured in inches of water column (in wc) or Pascals (Pa). The measurement range is
from 0.0001 to 60.00 in wc. Maximum safe pressures are 20 psid (900% full scale) and 60 psia common mode.
Accuracy is ± 2% of reading ± 0.001 in wc from 0.0500 to 50.00 in wc.
ABSOLUTE PRESSURE: Measured in inches of mercury (in Hg) or bars with reference to a vacuum. The measurement
range is 10-40 in Hg. Maximum safe pressure is 60 psia. Accuracy is ± 2% of reading ± 0.1 in Hg from 14 to 40 in
Hg.
TEMPERATURE: Accuracy is ± 0.5/F from 32/F to 158/F with a resolution of 0.1/F using the ADT442, ADT443, ADT444,
ADT445 or ADT446 TemProbes. AirData Multimeters display readings from -67.0/F to 250.0/F. Safe exposure
range for the TemProbes is -100/F to 250/F. Do not expose the plastic base of the TemProbe or the extension
wand to temperatures above 200/F.
AIR FLOW: Measured in cubic feet per minute (cfm) or liters per second (L/s), corrected for air density. This function
requires the use of the Shortridge Instruments, Inc. Series 8400 Backpressure Compensating FlowHood System.
The measurement range is 25 to 2500 cfm supply and 25 to 1500 cfm exhaust. Accuracy is ± 3% of reading ± 7 cfm
from 100 to 2000 cfm (nonbackpressure compensated readings).
AIR DENSITY CORRECTION: The air density correction range is 14-40 in Hg and 32/F to 158/F for correction of air flow
and velocity measurements. The readings represent either local density air flow or standard density sea level
equivalent (mass flow) for air flow or velocity. Readings are corrected for the density effects of temperature and
absolute pressure.
MEMORY: 2000 readings with sequential recall of each reading along with the average, sum, minimum, maximum and
standard deviation. Data may be stored in 25 separate memory groups.
RESPONSE TIME: Varies from one second at higher pressure inputs to seven seconds at less than 0.0003 in wc (70 fpm).
Extremely low pressure/flow/velocity inputs require longer sample times than higher pressure/flow/velocity inputs.
TREND mode provides continuous readings in less than two second intervals. (Accuracy specifications do not apply
in TREND mode).
READOUT: Ten digit, 0.4 inch, liquid crystal display (LCD).
METER HOUSING: High impact, molded, "T" grade ABS.
METER WEIGHT: 36 ounces (1.02 kg), including batteries.
SIZE: 6.0" x 6.4" x 2.7" (15.2 x 16.3 x 6.9 cm).
BATTERY LIFE: A ten-hour charge will normally allow two working days of heavy use, or up to 3000 readings per charge
if the backlight is not being used. Increasing the charge time to 48 hours (such as a weekend) will increase the
working time by 25%. Continuous use of the backlight may reduce the battery life by up to one half.
A set of rechargeable type AA NiCad batteries is supplied in each meter. Each battery has a storage capacity of
1100 milliAmp hours. These batteries may be recharged up to 500 times before replacement. If 1100 mAh batteries
are not available in a field situation, 700 mAh batteries (all 12 ) may be substituted. If 700 mAh batteries are mixed
with 1100 mAh batteries, the 700 mAh batteries may be damaged as the battery charge is depleted. If rechargeable
batteries are not available in a field situation, the batteries may be replaced with 12 non-rechargeable "AA" pen cell
batteries.
WARNING: Do not plug the charger in if any non-rechargeable batteries are in the meter. The meter will be
seriously damaged along with the batteries and charger.
The approximate level of charge remaining in the batteries may be displayed by pressing SHIFT/SHIFT. The display
will read BATT FULL if the batteries are highly charged. The display will read BATT 2/3, BATT 1/3, or LOCHARGE

ADM-880C 07/20/093
as the level of charge decreases. NOTE: A battery charge level displayed when the meter is first turned on may
not be representative of the true level of battery charge. Wait five or ten minutes after turning the meter on to view
the charge status.
BATTERY CHARGERS: The battery charger (P/N PS8201) used in the U.S.A. and many other countries requires 120 Volts
AC, 60Hz, 8W. The battery charger (P/N PS8202) used in Europe and certain other locations requires 220 Volts AC,
50Hz. Both chargers deliver 24 Volts AC to the meter. Batteries may be left on charge for an unlimited time
without harm. The temperature of the instrument during charge should be kept between 40/F and 113/F (5/C to
45/C). The meter is fully operational during recharge.
OPERATIONAL TEMPERATURE LIMITS: The specified accuracy for measurements is maintained over a meter exposure
temperature range of 40/F to 140/F (5/C to 60/C).
STORAGE TEMPERATURE LIMITS: -4/F to 140/F (-20/C to 60/C).
AIR BLEED: Each pressure measurement requires a small volume of air to pass through the meter. The pressure source
must be capable of supplying this volume without significant depletion to assure accurate measurements. Bleed
through is typically 0.0004 cubic inch per in wc per measurement. Quiescent bleed through (maximum) is 0.0005
cubic inch per in wc per minute.
TUBING: The maximum recommended length of pneumatic tubing for the measurement of air flow, velocity, or differential
pressure is 18 feet. Minimum tubing size is 3/16 inch, inside diameter. The VelGrid is used with the two eight foot
lengths of 3/16 inch ID tubing furnished with the kit.

ADM-880C 07/20/094
3.0 EXTERNAL FEATURES
External Read Jack for
Pushbutton Handle Plug
Pushbutton Reset
FIGURE 3.1 ADM-880C METER FRONT AND BACK
10 Digit, 0.4" LCD Display
Battery Charger Jack
Green LED indicates if charger is plugged in
RS232 Serial Port Jack
ALT Alters function of following key
ESCAPE Exits loop; displays current selections
MODE Flow/Press/Temp/VelGrid/AirFoil/Pitot
TIMED READ Set up for timed readings
CONFIGURE Set up Units, Density, Time, Date
VIEW View statistics
ASSOCIATED View Assoc Press, Temp, Time, Date
DOWNLOAD Download to printer
STORE Store in memory
CLEAR Clear memory
CHANGE Change mem group; erase; replace
READ Initiate reading; halt read sequence
SELECT Select displayed option
AUTO Automatic readings
TREND TREND readings
SCAN <Recall in entry order
=SCAN Recall in reverse order
GO TO Go To a designated reading
ON Power On; turn light On & Off
OFF Power Off after ALT
Positive (+) Pressure Port
Negative (-) Pressure Port
Flaps Jack for FlowHood Flaps Plug
Threaded Insert for Attachment to FlowHood
with Captive Screw
Calibration Label with Serial Number & Date
Temperature Input Jack for TemProbe,
Retractile Cord or MultiTemp
Battery Compartment Cover - Remove the 8
Small Phillips Head Screws to Test or Replace the
Batteries (12 AA NICAD)
Four Large Phillips Head Screws That Hold
the Meter Case Together - DO NOT REMOVE

ADM-880C 07/20/095
3.1 KEYPAD LAYOUT
There are eight keys on the keypad, arranged as shown below. Several keys have multiple functions.
ALT
ESCAPE
1 2 3 4
MODE
TIMED READ
CONFIGURE
5 6 7 8
VIEW
ASSOCIATED
DOWNLOAD
9 0
STORE
CLEAR
CHANGE
ON
OFF
<SCAN
GO TO
SCAN>
READ
SELECT
AUTO
TREND
KEY PRIMARY FUNCTION (F) SECONDARY FUNCTION (ALT / F) TERTIARY FUNCTION (ALT / F / ALT / F)
ALT Alternate Escape
MODE MEASUREMENT TIMED READ CONFIGURE
Differential pressure Interval Time Units - English or Metric
Temperature Begin Time Density - Local or Standard
VelGrid velocity End Time Time
AirFoil velocity Number of Readings Date
Pitot tube velocity
Absolute pressure
FlowHood air flow
VIEW STATISTICS ASSOCIATED DATA DOWNLOAD
Average Mode/Units Download to printer
Sum Temperature
Minimum Absolute pressure
Maximum Differential pressure
Standard deviation Time and date
STORE STORE CLEAR MEMORY CHANGE MEMORY
Store All Select memory group
Store Last Erase reading in memory
Store Off Replace reading in memory
ON If meter off, turn on Turn meter off
If meter on, turn light on
If light on, turn light off
=SCAN Scan memory sequence Go To
ascending
SCAN<Scan memory sequence Reset display
descending
READ Read/Select Automatic Readings Trend Readings

ADM-880C 07/20/096
3.3 FEATURES ON SIDES AND BACK OF METER
BATTERY CHARGER JACK
When viewed from the front, the battery charger jack is on the right side of the meter toward the top. The battery
charger plug is to be connected here.
EXTERNAL READ JACK
When viewed from the front, the external read jack is on the left side of the meter toward the top. The plug for the
external thumbswitch is connected here. This feature allows the operator to trigger measurements from the
FlowHood or VelGrid handgrip while working overhead or in awkward circumstances. The thumbswitch performs
the same function as the READ key.
FLAPS JACK
The flaps jack is on the back of the meter, in the upper right hand corner. The flaps plug on the FlowHood is inserted
here.
TEMPERATURE INPUT JACK
The temperature input jack is centered on the back of the meter, slightly toward the top. The flexible TemProbe
sensor must be connected to this receptacle whenever temperature density correction is desired for either flow or
velocity measurements. A retractile cord connects the TemProbe or the MultiTemp to the temperature input jack
for remote temperature sensing.
RESET SWITCH
The reset pushbutton switch is on the back of the meter in a recess near the upper left corner. This switch is used
to reset the meter in the unlikely event that the microprocessor becomes lost in its program. This may occur if the
meter is dropped, and may cause the keypad to become nonfunctional until the meter is reset. Press the reset switch
for one second to restart the meter.
Readings saved in memory since the meter was last turned on may be lost if the meter must be reset. If the meter
continues to fall into "lockout" after being reset, it may have been damaged, and should be returned for repair.
PNEUMATIC PRESSURE INLETS
Two pneumatic pressure inlets positive (+) and negative (-) are centered on the back of the meter at the top edge
and may be connected to various pressure sources for the measurement of air velocity, flow, or pressure. Sources
include the FlowHood, AirFoil probe, VelGrid, pitot tubes, static pressure probes, or any other pressure source not
exceeding the safe limits for the meter. The negative (-) inlet senses the static pressure during flow or velocity
measurements, and also is used for direct absolute pressure measurements.
SERIAL PORT JACK
When viewed from the front, the serial port jack is centered on the right side of the meter just below the battery
charger jack. The circular plug of a custom RS232 serial cable is connected here. The other end of the cable
provides a standard DB9 connection for a printer or computer.

ADM-880C 07/20/097
4.0 DISPLAY MESSAGES AND PROMPTS
The display messages and prompts displayed by the meter are listed alphabetically within this section. Display messages
and prompts are shown within square brackets throughout the text in other sections of this Instruction Manual. An AirFoil
probe reading in MANUAL reading mode is shown as [FP ± nnnn].
Manual and automatic reading prompts and measurement displays have a battery symbol ( ) as the third or fourth character
of the display. This battery symbol indicates the level of charge in the batteries. This battery symbol is not generally shown
in the text throughout this manual.
If either the STORE or AUTO STORE mode has been selected, the read prompts and measurement displays have a letter
as the first character to the right of the reading sequence number. This letter represents the memory grouping and is not
generally shown in the text throughout this manual. Where it is shown in the manual, it is represented by the letter “G”.
An AirFoil probe reading in either STORE mode is shown as [nnG ± nnnn]. When the charge in the batteries begins to fail,
the letter representing the memory group will be replaced by the symbol for an empty battery.
If the TREND mode has been selected, the measurement displays have an arrow as the first character to the right of the
units abbreviation. When the charge in the batteries begins to fail, the message [LOCHARGE] will be displayed after every
30 readings displayed.
4.1 READ PROMPTS
The following ten prompts all include the term READ, which is a signal for the operator to press the READ key to trigger
the actual measurement.
English Units
CF READ
This display indicates that the meter has been placed in the air flow measurement mode (cfm). This message will
appear automatically upon power up if the flaps plug of the FlowHood is connected to the meter.
/F READ
This display indicates that the meter has been placed in the temperature measurement mode (/F).
FP READ
This display indicates that the meter has been placed in a velocity measurement mode (fpm).
Hg READ
This display indicates that the meter has been placed in the absolute pressure measurement mode (in Hg) with
reference to a vacuum.
In READ
This display indicates that the meter has been placed in the differential pressure measurement mode (in wc).
Metric Units
Bar READ
This display indicates that the absolute pressure readings will be displayed in bars (1 bar = 100 kPa) with reference
to a vacuum.
/C READ
Display indicates that the temperature readings will be displayed in degrees Celsius (/C).
LS READ
This display indicates that the meter has been placed in the air flow measurement mode and will read in liters per
second (L/s).
MS READ
This display indicates that the velocity readings will be displayed in meters per second (m/s).
Pa READ
This display indicates that differential pressure readings will be displayed in Pascals (Pa).
4.2 MEASUREMENT READOUTS
In the following 12 examples, n indicates a number in the displayed result. If no sign is displayed, the result is a positive
number. A negative sign indicates a negative number. English and metric units are shown for each example.

ADM-880C 07/20/098
English Units
CF c ± nnnn
Indicates that the result represents an air flow measurement (cfm). "C" indicates that the result has been
compensated for backpressure effects.
CF u ± nnnn
Indicates that the result represents an air flow measurement (cfm). "U" indicates that the result has not been
compensated for backpressure effects.
FP ± nnnn
Indicates that the displayed result represents a velocity measurement (fpm).
/F ± nnn.n
Indicates that the displayed result represents a temperature measurement (/F).
Hg ± nn.n
Indicates that the result represents an absolute pressure measurement (in Hg).
In ± n.nnnn
Indicates that the result represents a differential pressure measurement (in wc).
Metric Units
Bar n.nnn
Indicates that the result represents an absolute pressure measurement (bar). (One bar = 100 kPa).
/C ± nnn.n
Indicates that the displayed result represents a temperature measurement (/C).
LS c ± nnnn
Indicates that the result represents an air flow measurement (L/s). "C" indicates that the result has been
compensated for backpressure effects.
LS u ± nnnn
Indicates that the result represents an air flow measurement (L/s). "U" indicates that the result has not been
compensated for backpressure effects.
Pa ± nnn.nn
Indicates that the result represents a differential pressure measurement (Pa).
MS ± nnn.nn
Indicates that the displayed result represents a velocity measurement (m/s).
4.3 FUNCTION READOUTS
The following prompts and messages are listed in alphabetical order.
$$$$$$$$
Blocks of pixels will be displayed to test the operation of the display each time the meter is turned on.
nnnn M
This display is used to enter the number of timed readings required in a timed reading sequence.
nn:nn:nnB
This display is used to set the BEGIN TIME for the TIMED READ mode and is also used to display the time after the
setup has been completed. The display follows the [HH:MM:SS B] sequence, where HH is the hour, MM is the
minutes and SS is the seconds. The letter B at the right represents BEGIN. If the meter has been set to a 12 hour
clock, the letter A for am or P for pm will be displayed to the left of the letter B.
nn:nn:nnE
This display is used to set the END TIME for the TIMED READ mode and is also used to display the time after the
setup has been completed. The display follows the [HH:MM:SS E] sequence, where HH is the hour, MM is the
minutes and SS is the seconds. The letter E at the right represents END. If the meter has been set to a 12 hour
clock, the letter A for am or P for pm will be displayed to the left of the letter E.

ADM-880C 07/20/099
nn:nn:nnI
This display is used to set the INTERVAL TIME for the TIMED READ mode and is also used to display the time after
the setup has been completed. The display follows the [HH:MM:SS I] sequence, where HH is the hour, MM is the
minutes and SS is the seconds. The letter I at the right represents INTERVAL.
nn:nn:nnT
This message displays the time settings for the meter after the setup has been completed. The display follows the
[HH:MM:SS T] sequence, where HH is the hour, MM is the minutes and SS is the seconds. The letter T at the right
represents TIME. If the meter has been set to a 12 hour clock, the letter A for am or P for pm will be displayed to
the left of the letter T.
nnG n.nnnn
Displays a reading and its place in the reading sequence within its memory group during an AUTO or MANUAL
STORE sequence. Number of decimal places will vary.
nn NP 0
Indicates that the reading being displayed in an AUTO or MANUAL STORE sequence is a negative pitot tube
reading.
nn c nnnn
This message indicates that backpressure compensated air flow readings have been stored. The display shows the
reading and its order in the stored reading sequence.
nn ERASED
This message is displayed after a listed reading is erased. The erased reading will not be included in subsequent
calculations of statistics for the memory group.
nn u nnnn
This message indicates that nonbackpressure compensated air flow readings have been stored. The display shows
the reading and its order in the stored reading sequence.
nn0n.nnnn
Displays the number of readings in memory and the average of the readings. Displayed when the VIEW key is
pressed once during a MANUAL STORE sequence or after HALT during a AUTO STORE sequence. Number of
decimal places will vary.
3n.nnnn
Displays the sum of the readings in memory. Displayed when the VIEW key is pressed twice during a MANUAL
STORE sequence or after HALT during a AUTO STORE sequence. Number of decimal places will vary.
Fn.nnnn
Displays the standard deviation of the readings in memory. Displayed when the VIEW key is pressed five times
during a MANUAL STORE sequence or after HALT during a AUTO STORE sequence. Number of decimal places
will vary.
xx n.nnnn
This display indicates that the battery charge is nearly depleted. xx indicates the units for the reading. The meter
will also begin displaying LOCHARGE periodically.
xx n.nnnn
This display indicates that the battery is highly charged. xx indicates the units for the reading. The area of the
battery symbol that is dark will decrease incrementally as the battery charge declines.
xx6n.nnnn
This display indicates that the meter is in TREND mode and that the readings are remaining relatively constant. xx
indicates the units for the reading.
xx_n.nnnn
This display indicates that the meter is in TREND mode and that the readings are increasing slowly. xx indicates
the units for the reading.

ADM-880C 07/20/0910
xx8n.nnnn
This display indicates that the meter is in TREND mode and that the readings are increasing rapidly. xx indicates
the units for the reading.
xx`n.nnnn
This display indicates that the meter is in TREND mode and that the readings are decreasing slowly. xx indicates
the units for the reading.
xx9n.nnnn
This display indicates that the meter is in TREND mode and that the readings are decreasing rapidly. xx indicates
the units for the reading.
xx¸n.nnnn
Displays the maximum (greatest value) reading for a given measurement mode stored in a specific memory group
during a STORE sequence. Displayed when a particular reading in that measurement mode within that memory
group has been selected using a SCAN key, and the VIEW key is pressed four times. Number of decimal places
will vary.
xxºn.nnnn
Displays the minimum (least value) reading for a given measurement mode stored in a specific memory group
during a STORE sequence. Displayed when a particular reading in that measurement mode within that memory
group has been selected using a SCAN key, and the VIEW key is pressed three times. Number of decimal places
will vary.
12-HR s
This prompt indicates that a 12 hour clock is being selected using the meter configuration loop.
24-HR s
This prompt indicates that a 24 hour clock is being selected using the meter configuration loop.
ABS PRES
This signal will be flashed when the absolute pressure measurement mode is selected, and also each time the READ
key is pressed when in the absolute pressure measurement mode. It is also part of the ASSOCIATED READING
sequence and precedes the display of an absolute pressure reading associated with a flow or velocity reading.
ADM-880C
This message is flashed following $$$$$$$$when the meter is first turned on.
AIRFOIL
This signal will be flashed when the AirFoil probe measurement mode is selected and also upon each subsequent
operation of the READ key.
ALT
This message is displayed when the ALT key is pressed.
ASSOCIATED
This message is briefly displayed when ALT / VIEW is pressed while a selected reading in memory is being
displayed. User may toggle through the associated reading displays by pressing the VIEW key repeatedly.
AUTO
This message is displayed as part of the overall meter status if the user presses ALT / READ to display [AUTO
READY], then presses ALT / ALT instead of READ. It indicates that the meter is still ready to initiate an automatic
reading sequence, and will do so if the user presses READ.
AUTO READY
This message indicates that the meter has been placed in the automatic reading function. Press the READ key to
start the automatic reading sequence. Press the READ key to HALT the reading process. [HALT] will be displayed.
AUTO STORE
This message indicates that the meter has been placed in the automatic memory mode, which integrates the
automatic reading function with the sequential storage function, and permits recall of the readings, sum, average and
standard deviation at any point. Press the READ key to initiate the actual reading process. Press the READ key
again to stop the automatic reading sequence. [HALT] will be displayed. Press ALT / AUTO / STORE to resume the

ADM-880C 07/20/0911
store sequence within the same memory group.
AUTO ZERO
When the meter is first turned ON, it will perform a self-calibration process that takes a few seconds. The display
will read [AUTO ZERO] during this period and the operating controls will be inhibited. No READ operations or
function changes may be made during the AUTO ZERO period. The meter will also perform a brief self-calibration
cycle periodically throughout normal operation.
BATTERY
This message will appear as part of the [NO LIGHT / BATTERY / TOO LOW] display sequence, when the battery
charge is too low to support use of the light.
BATT 1/3
This message indicates that about 1/3 of the useful battery charge remains. This message is displayed every five
minutes in MANUAL reading mode and also after pressing ALT / ALT.
BATT 2/3
This message indicates that about 2/3 of the useful battery charge remains. This message is displayed every five
minutes in MANUAL reading mode and also following ALT / ALT.
BATT FULL
This message indicates that the batteries are fully (or close to fully) charged. This message is displayed every five
minutes in MANUAL reading mode and also following ALT / ALT.
BEGIN WAIT
This message indicates that the meter is in TIMED READ mode and is waiting for the Begin Time to occur.
CALC STATS
This message is displayed while the meter is calculating the statistics for a large memory group.
CHANGE
This message indicates that a connection to the meter, such as the TemProbe, has been altered. [CHANGE] may
be preceded by the display of the connection type.
CHANGE MEM
This message is flashed when the user presses ALT / STORE / ALT / STORE to access the function to select a new
memory group, erase a reading or replace a reading in memory.
CHANGE / NOT ALLOWD
This message is displayed in sequence with other messages to indicate that a selected function is not available.
CHG GROUPs
This message is displayed to prompt the user to press the SELECT key to select a new memory group.
?CLR ALL? s
This message indicates that the meter has more than 50 readings in one memory group or is using more than one
memory group and all readings will be deleted from memory when the READ / SELECT key is pressed.
CLEAR
This message is displayed when the operator has pressed ALT / STORE / SELECT and no readings are in memory.
CLEAR AUTO
This message is flashed if the user presses ALT / READ to display [AUTO READY] , then presses ALT / STORE
/ SELECT. The meter displays this message briefly and returns to the MANUAL reading mode.
CLEAR MEMs
This message is displayed when the operator has pressed ALT / STORE, and is the prompt to press the READ key
to clear all readings in memory.
CLEAR TREN
This message is flashed if the user presses ALT / READ / ALT / READ to display [TREND RDY], then presses ALT
/ CLEAR / SELECT. The meter displays this message briefly and returns to the MANUAL reading mode.

ADM-880C 07/20/0912
CONFIGURE
This message is flashed if the user presses ALT / MODE / ALT / MODE and indicates that the configuration loop has
been selected by the user.
CORR
Part of the FLO-HOOD / CORR message sequence. This message sequence indicates that the meter is taking a
FlowHood reading that is compensated for backpressure..
DATA ERROR
This message indicates that a number has been entered which is not appropriate for that type of data entry, such
as a three for the first digit of the hour setting for time.
DATE s
This is the fourth option available when the user presses the MODE key repeatedly after selecting the CONFIGURE
mode, and is used to change the date settings in the meter.
DENSITY / CHANGE / NOT ALLOWD
This message is displayed if the density selection is changed while readings are being stored in an air flow or velocity
measurement mode. A change in the density selection while storing air flow or velocity readings requires the user
to select a new memory group, as readings stored with local and standard densities must not be averaged together.
DENSITY s
This is the second option available when the user presses the MODE key repeatedly after selecting the CONFIGURE
mode and is used to change the density settings in the meter.
DIFF PRES
This signal will be flashed when the differential pressure measurement mode is selected, and upon each subsequent
operation of the READ key. It is also displayed as part of the sequence of displays when the associated readings
are being viewed by pressing ALT / VIEW following a pitot tube velocity reading. It precedes the display of the
velocity pressure read by the meter to produce the pitot tube reading.
D PRESS IN
This message is displayed as part of the sequence of displays when associated readings are being viewed following
a differential pressure reading.
ENGLISH
This message indicates that the readings will be in English units. The meter will save the units selection (metric or
English) and will automatically default to the selected units the next time it is turned on.
ENGLISH s
This prompt indicates that English units are being selected using the meter configuration loop.
ERASE s
This message is displayed when the operator has pressed ALT / STORE / ALT / STORE, followed by pressing the
STORE key twice while viewing a stored reading. The reading displayed will be erased when the operator presses
the READ/SELECT key.
ERASING
This message is displayed when the selected reading displayed using a SCAN key is being erased.
ESCAPE
This message is displayed when the user presses ALT / ALT. The meter will revert to the prior selections.
FLO-HOOD
This message will be flashed when the FlowHood measurement mode is selected, or when the meter is first turned
on, if the flaps plug is connected.
FLO-HOOD / CORR
This message sequence indicates that the meter is taking a FlowHood reading that is compensated for backpressure.
FLO-HOOD / UNCORR
This message sequence indicates that the meter is taking a FlowHood reading that is not compensated for
backpressure.

ADM-880C 07/20/0913
FLOW H CFM
This message is part of the ASSOCIATED READING sequence and precedes the display of the temperature and
absolute pressure readings associated with an air flow reading.
FLOW ONLY
[FLOW ONLY] will be displayed if the operator inserts the FlowHood flaps plug while the meter is in a velocity or
differential pressure measurement mode and presses the READ key.
GRP IN USE
This message is displayed to indicate that the user is selecting a memory group that is currently in use, or already
has been used. New readings can not be added to a memory group after it has been exited.
HALT
This message will be displayed when an automatic reading, automatic reading storage, or TREND mode sequence
has been halted manually by pressing the READ key. The individual readings, or the average, total, minimum,
maximum and standard deviation of the readings, may now be displayed if the auto-reading memory function is being
used.
If the TREND mode is being used, the meter will revert to the MANUAL reading mode and the last reading displayed
will be a standard MANUAL reading.
LIGHT OFF
This message indicates that the display backlight has been turned off. Battery time is extended when the backlight
is turned off.
LIGHT ON
This message indicates that the display backlight has been turned on. Battery time is reduced when the backlight
is turned on.
LOCAL DENS
This message indicates that flow or velocity readings will be corrected for local air density. The meter automatically
starts up in the local density mode, unless the meter was last turned off with readings stored in the standard density
mode.
LOC DENS s
This prompt indicates that local density is being selected using the meter configuration loop.
LOCHARGE
This message indicates that the battery cells are nearing the end of their useful charge. The meter will continue to
function normally for about twenty minutes, depending on light use, before recharge is required. The third character
of all MANUAL, AUTO and STORE readings will become the symbol for an empty battery cell.
MANUAL
This message is flashed when the user halts a series of TREND readings, as the meter reverts to the MANUAL mode
and takes a final, MANUAL reading.
MEM CLEAR
This message is flashed when the ALT / CLEAR keys are pressed to clear the AUTO STORE mode.
MEM EMPTY
This message indicates that the meter is in STORE mode, but no readings have been saved.
METRIC
This message indicates that the readings will be in metric units. This option is selected using the CONFIGURE loop,
which is accessed by pressing ALT / MODE / ALT / MODE. [UNITS s] is displayed as the first option. Press the
READ key to select the UNITS loop. Press the MODE key to toggle between metric and English units, then press
the READ key to select the units required. The meter will save the units selection (metric or English) and will
automatically default to the selected units the next time it is turned on.
METRIC s
This prompt indicates that metric units are being selected using the meter configuration loop.
MODE CHANG / NOT ALLOWD

ADM-880C 07/20/0914
This message sequence is displayed when a change in setup would invalidate the result in incompatible readings.
MODE / UNITS
This message sequence is displayed when the ASSOCIATED function has been selected. It is followed by a display
of the measurement mode and units for that particular reading.
NEG PITOT
This message indicates an invalid, negative, pitot tube velocity reading. This may result from reversed tubing
connections to the meter, or from other conditions described in the section on PITOT TUBE VELOCITY
MEASUREMENT.
NO FLAPS
This message advises that the flaps plug on the FlowHood has not been connected to the meter for air flow
measurements. The meter senses the position of the flaps through the flaps plug.
NO LIGHT
This message will appear as part of the [NO LIGHT / BATTERY / TOO LOW] sequence, when the battery charge
is too low to support use of the backlight.
NO LIGHT / BATTERY / TOO LOW
This sequence of messages indicates that the battery charge is low and the backlight may not be used until the
batteries are recharged.
NO PROBE
This message appears when the operator has neglected to install the TemProbe sensor prior to initiating a
temperature measurement. This term is also displayed if the TemProbe or extension cord has been damaged so
as to create an open circuit.
NO READING
This is part of the ASSOCIATED READING sequence and is displayed when an associated reading is not available
for that type of primary reading.
NO STATS
This message is displayed when the VIEW key is pressed while there are no readings in memory.
NOT A GRP
This message is displayed when an empty memory group is selected using the ALT / =SCAN function.
NOT ALLOWD
This message is displayed if the user tries to select the STORE mode while in TREND mode and in sequence with
other messages to indicate that a selected function is not available.
NP 0
This message is displayed when a stored negative pitot tube reading is viewed using a SCAN key.
OPEN FLAPS
This message advises that the operator has attempted to perform a nonbackpressure compensated air flow
measurement at greater than 500 cfm with the flaps closed. The flaps must be opened to proceed.
OVER FLOW
This display advises the operator that the air flow measurement being attempted is beyond the range of the meter.
OVER PRES
This display advises the operator that the pressure measurement being attempted is beyond the range of the meter.
[OVER PRES] may also be displayed if internal voltage settings or linearity is out of proper range. (Contact the
factory if the meter continues to read [OVER PRES] at inappropriate times).
OVER TEMP
This display advises the operator that the temperature measurement being attempted exceeds the upper range of
the meter.

ADM-880C 07/20/0915
OVER VEL
This display advises the operator that the velocity measurement being attempted is beyond the range of the meter.
[OVER VEL] may also be displayed if internal voltage settings are out of proper range. (Contact the factory if the
meter continues to read [OVER VEL] at inappropriate times).
PITOT TUBE
This signal will be flashed when the pitot tube measurement mode is selected, and also upon each subsequent
operation of the READ key.
PRESS READ
Please refer to [TIMED RDY / PRESS READ].
PRINTER s
This prompt is displayed when the operator has selected the PRINT mode. If an appropriate printer is connected
to the RS232 jack on the meter, and the READ key is pressed, the entire contents of the memory will be downloaded
to the printer.
PRINTING
This message is displayed when the operator is printing readings from memory.
PROBE
This message is displayed following ALT / ALT if the TemProbe is connected.
RATIO ERR
This message advises the operator that the backpressure compensated air flow measurement, which is in process,
is invalid because the numerical ratio of the two parts of the measurement sequence exceeds the predetermined
limits. Normally, this means that the operator has made a procedural error, or that a dynamic change (such as a
changed damper setting) has occurred between the two parts of the backpressure compensated air flow
measurement process.
READING
This is part of the ASSOCIATED reading sequence and precedes the final display of the primary reading selected
by the user.
RECHARGE
This message signals that the batteries have reached the end of their useful charge, and must be recharged. The
meter will turn off following the display of [RECHARGE / SHUT DOWN].
REPLACE s
This message is displayed when the operator has pressed ALT / STORE / ALT / STORE followed by the STORE
key while viewing stored readings. This message indicates the current reading displayed will be replaced with a new
reading when the operator presses the READ key.
REPLACING
This message is displayed when the current reading displayed is being replaced with a new reading.
SHUT DOWN
The meter will display [SHUT DOWN] and turn itself off if the battery charge becomes too low or if the meter is
exposed to temperatures beyond the specified limits.
STATS
This message is displayed when the user selects a reading stored in memory, and then presses the VIEW key. The
sum, average, minimum, maximum and standard deviation of all readings of the same measurement mode within
that memory group will be displayed sequentially.
STD 70/F or STD 21.1/C
This message will be flashed during air flow or velocity measurements performed without the TemProbe. The
resulting flow or velocity value will be calculated using the standard temperature, 70/F or 21.1/C. The correction
for the ambient barometric pressure will still occur.
STD DENS
This message indicates that readings will be calculated to display standard density sea level equivalent (mass flow).
It will also be displayed during the actual measurement interval.