TSI Incorporated VelociCalc Plus 8384 Operation manual

Indoor Air Quality
VELOCICALC®Plus
Air Velocity Meter
Models 8384/8384A/8385/
8385A/8386/8386A
Operation and Service Manual
1980321, Revision J
July 2010
ENERGY AND COMFORT

Copyright
TSI Incorporated / August 2000–2010 / All rights reserved.
Address
TSI Incorporated / 500 Cardigan Road / Shoreview, MN 55126 / USA
Fax No.
[phone]
LIMITATION OF WARRANTY AND LIABILITY (effective July 2000)
Seller warrants the goods sold hereunder, under normal use and service as described in the
operator's manual, shall be free from defects in workmanship and material for twenty-four (24)
months, or the length of time specified in the operator's manual, from the date of shipment to the
customer. This warranty period is inclusive of any statutory warranty. This limited warranty is
subject to the following exclusions:
a. Hot-wire or hot-film sensors used with research anemometers, and certain other
components when indicated in specifications, are warranted for 90 days from the date of
shipment.
b. Parts repaired or replaced as a result of repair services are warranted to be free from
defects in workmanship and material, under normal use, for 90 days from the date of
shipment.
c. Seller does not provide any warranty on finished goods manufactured by others or on any
fuses, batteries or other consumable materials. Only the original manufacturer's warranty
applies.
d. Unless specifically authorized in a separate writing by Seller, Seller makes no warranty
with respect to, and shall have no liability in connection with, goods which are
incorporated into other products or equipment, or which are modified by any person other
than Seller.
The foregoing is IN LIEU OF all other warranties and is subject to the LIMITATIONS stated
herein. NO OTHER EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR
PARTICULAR PURPOSE OR MERCHANTABILITY IS MADE.
TO THE EXTENT PERMITTED BY LAW, THE EXCLUSIVE REMEDY OF THE USER OR
BUYER, AND THE LIMIT OF SELLER'S LIABILITY FOR ANY AND ALL LOSSES,
INJURIES, OR DAMAGES CONCERNING THE GOODS (INCLUDING CLAIMS BASED
ON CONTRACT, NEGLIGENCE, TORT, STRICT LIABILITY OR OTHERWISE) SHALL
BE THE RETURN OF GOODS TO SELLER AND THE REFUND OF THE PURCHASE
PRICE, OR, AT THE OPTION OF SELLER, THE REPAIR OR REPLACEMENT OF THE
GOODS. IN NO EVENT SHALL SELLER BE LIABLE FOR ANY SPECIAL,
CONSEQUENTIAL OR INCIDENTAL DAMAGES. SELLER SHALL NOT BE
RESPONSIBLE FOR INSTALLATION, DISMANTLING OR REINSTALLATION COSTS
OR CHARGES. No Action, regardless of form, may be brought against Seller more than 12
months after a cause of action has accrued. The goods returned under warranty to Seller's
factory shall be at Buyer's risk of loss, and will be returned, if at all, at Seller's risk of loss.
Buyer and all users are deemed to have accepted this LIMITATION OF WARRANTY AND
LIABILITY, which contains the complete and exclusive limited warranty of Seller. This
LIMITATION OF WARRANTY AND LIABILITY may not be amended, modified or its terms
waived, except by writing signed by an Officer of Seller.
Service Policy
Knowing that inoperative or defective instruments are as detrimental to TSI as they are to our
customers, our service policy is designed to give prompt attention to any problems. If any
malfunction is discovered, please contact your nearest sales office or representative, or call TSI's
Customer Service department at [phone] (USA) and 1 [phone] (International).

CONTENTS
Chapters
1. UNPACKING AND PARTS IDENTIFICATION...............................1
Parts Identification..........................................................................2
2. SETTING-UP ...................................................................................3
Supplying Power to the VELOCICALC Plus ......................................3
Installing the Batteries...............................................................3
Using the Optional AC Adapter.................................................3
Selecting the Display Units.............................................................3
Using The Telescoping Probe........................................................3
Extending The Probe.................................................................4
Retracting The Probe................................................................4
Articulating Probe (Models 8384A/8385A/8386A Only)............4
Changing the Real-Time Clock.......................................................4
Changing the Baud Rate................................................................4
Connecting the Optional Portable Printer.......................................5
Connecting to a Computer..............................................................5
3. OPERATION....................................................................................7
Keypad Functions...........................................................................7
Common Terms..............................................................................7
ON/OFF Key......................................................................................7
Arrow () Keys...........................................................................8
ENTER Key.......................................................................................8
Backlight Switch..............................................................................8
VELOCITY/FLOWRATE Key.................................................................8
PRESSURE (zero) Key (Models 8385/8385A/8386/8386A Only).....9
TEMPERATURE Key ..........................................................................9
HUMIDITY Key (Model 8386/8386A Only)......................................10
THERMAL/PITOT Key (Models 8385/8385A/8386/8386A Only)......10
ACTUAL/STANDARD Key..................................................................10
SAMPLE INTERVAL Key ...................................................................10
SAMPLE (options) Key....................................................................11
Discrete Data Logging (Single Point Measurements).............11
Continuous Data Logging (Multiple Readings Over Time)......11
Setting Data Storage Options..................................................11
NEXT TEST (clear) Key...................................................................13
STATISTICS (review data) Key........................................................13
To View Statistics....................................................................13
To Review Data.......................................................................13
HEAT FLOW Key (Model 8386/8386A Only)...................................14
Printing Data Using the Portable Printer ......................................15

Downloading Data to A Computer................................................15
Data Acquisition (Polling)..............................................................16
4. MAINTENANCE.............................................................................17
Recalibration.................................................................................17
Cases............................................................................................17
Storage..........................................................................................17
5. TROUBLESHOOTING...................................................................19
Appendixes
A. SPECIFICATIONS ........................................................................21
B. DIP SWITCH SETTINGS ..............................................................25

1
Chapter 1
Unpacking and Parts Identification
Carefully unpack the instrument and accessories from the shipping
container. Check the individual parts against the list of components in
Table 1-1. If anything is missing or damaged, notify TSI immediately.
Table 1-1: List of Components
Qty
Item Description
Part /
Model
1
Model 8384 V
ELOCI
C
ALC
Plus or
8384
Model 8384A V
ELOCI
C
ALC
Plus (articulating probe) or
8384A
Model 8385 V
ELOCI
C
ALC
Plus or
8385
Model 8385A V
ELOCI
C
ALC
Plus (articulating probe) or
8385A
Model 8386 V
ELOCI
C
ALC
Plus or
8386
Model 8386A V
ELOCI
C
ALC
Plus (articulating probe)
8386A
1
Carrying Case
1319156
4
AA Alkaline Batteries
1208013
1
AC Adapter (optional)
120 V, NEMA-5, 60 Hz, or
230 V, European, CEE 7/16, 50 Hz or
230 V, Great Britain, 50 Hz, or
240 V, Australian, 50 Hz
2613033
2613078
800169
2613106
1
Operation and Service Manual
1980321
1
Static Pressure Tip
3002017
1
Pitot Tube (optional)
3002018
8 ft.
Rubber Tubing
801039
1
Interface Cable (Instrument to Computer)
8940
1
Downloading Software
800832

Chapter 1
2
Parts Identification
Figure 1-1: VELOCICALC Plus
1. Backlight Switch
5. Pressure Measurement Ports
2. Display
6. Battery Access Cover
3. Keypad
7. AC Adapter port
4. Probe Mounting Clips
8. Printer Output / Communications Port
4
2 6 5
1
3
8
7

3
Chapter 2
Setting-up
Supplying Power to the VELOCICALC Plus
The VELOCICALC Plus can be powered in one of two ways: four size AA
batteries or the optional AC adapter.
Installing the Batteries
Insert four AA batteries as indicated by the diagram located on the
inside of the battery compartment. The VELOCICALC Plus is designed to
operate with either alkaline or NiCd rechargeable batteries. Battery life
will be shorter if NiCd batteries are used. Carbon-zinc batteries are not
recommended because of the danger of battery acid leakage.
Table 2-1 Typical Battery Life at 20°C
Air Velocity
Alkaline
(ft/min)
(m/s)
(hrs)
100
0.5
>8.0
5000
25.0
5.0
Using the Optional AC Adapter
When using the AC adapter, the batteries (if installed) will be bypassed.
The AC adapter is not a battery charger. Be sure to provide the correct
voltage and frequency which is marked on the back of the AC adapter.
Selecting the Display Units
The VELOCICALC Plus is capable of displaying the measured values in
several different measurement units. To change the display units on your
VELOCICALC Plus, refer to Appendix B, DIP Switch Settings.
Using the Telescoping Probe
The telescoping probe contains the velocity, temperature, and humidity
sensors (humidity sensor, Models 8386 and 8386A only). When using the
probe, make sure the sensor window is fully exposed and the orientation
dimple is facing upstream. NOTE: For temperature and humidity
measurements, make sure that at least 3 inches (7.5 cm) of the probe is in
the flow to allow the temperature and humidity sensors to be in the air
stream.

4Chapter 2
Extending the Probe
To extend the probe, hold the handle in one hand while pulling on the
probe tip with the other hand. Do not hold the cable while extending the
probe as this prevents the probe from moving.
Retracting the Probe
To retract the probe, hold the handle in one hand while pushing on the
probe tip with the other hand. If you feel the probe antenna binding, pull
gently on the probe cable until the smallest antenna section is retracted.
Collapse the rest of the antenna by pressing the probe tip.
Articulating Probe (Models 8384A/8385A/8386A Only)
The articulating probe has the ability to bend at a 90° angle for those
hard to reach places. To bend the probe, loosen the knurled nut on the
joint, bend the probe, and tighten the nut. To straighten the probe,
loosen the nut, straighten the probe, and tighten the nut.
Changing the Real-Time Clock
The VELOCICALC Plus has an internal real-time clock that keeps track of the
time of day (the format is HH.MM where HH is the hour in 24-hour format
and MM is minutes) and the date. It is very important to set the time and
date correctly, otherwise date and time stamping of recorded data will not be
correct. This information has been set to Central Time at the factory before
shipping.
To change the time and date, press and hold both and keys during the
power-up sequence when the time is displayed. Release the keys when the
VELOCICALC Plus beeps twice. You will have an opportunity to view and/or
change the hours, minutes, year, month, and day of month in sequence. Use
the up and down arrow keys () to change any settings. Use the ENTER
key to store each setting and advance to the next one.
Changing the Baud Rate
The VELOCICALC Plus has a variable baud rate that is used when
downloading or printing data from the instrument. By changing the baud rate
to a higher rate, the data will be downloaded faster. NOTE: The baud rate
must be equal to that of your computer or printer.
The instrument baud rate is displayed during the initial power up sequence.
To change the baud rate, press and hold both and keys during the
power-up sequence while the baud rate is displayed. Release the keys when
the VELOCICALC Plus beeps twice. Use the and keys to scroll through
the available values of 1200, 2400, 4800, 9600, and 19200. Press ENTER to
set the value that is displayed.

Setting-up 5
Connecting the Optional Portable Printer
To connect the printer to the VELOCICALC Plus, locate the Printer Interface
Cable (supplied with the optional printer) and connect the 9-pin end labeled
“PRINTER” to the printer and the other end to the data port of the
VELOCICALC Plus.The printer must be set to the same baud rate as the
VELOCICALC Plus. See Changing the Baud Rate section for details on how
to change the baud rate for the VELOCICALC Plus. To change the baud rate
of the printer, please refer to that operation and service manual. Always turn
the VELOCICALC Plus on before the printer. If the printer prints question
marks (??????), asterisks (******), or random characters, reset it by turning
it off and then on again. If necessary, refer to the Portable Printer Manual.
Connecting to a Computer
Use the Computer Interface Cable provided with the VELOCICALC Plus to
connect the instrument to a computer for downloading stored data or for
remote polling. Connect the 9-pin end labeled “COMPUTER” to the
computer COM port and the other end to the data port of the VELOCICALC
Plus.A 9-pin to 25-pin adapter will be required if your computer has a 25-
pin serial port connector.
For more information on how to download stored data see Chapter 3 section
titled Downloading Data to a Computer. For polling instructions, see
Chapter 3 section titled Data Acquisition (Polling).
Caution: This symbol is used to indicate that the data port
of the VELOCICALC Plus is not intended for connection to a
public telecommunications network. Connect the data port
only to another RS232 port.

7
Chapter 3
Operation
Keypad Functions
When pressing the keys on the front panel, the VELOCICALC Plus will beep
to confirm the function. If you press a key and the VELOCICALC Plus does
not beep, then the VELOCICALC Plus does not allow that function during the
selected mode.
Common Terms
In this manual there are several terms that are used in different places. The
following is a brief explanation of the meanings of those terms.
Sample:Consists of all of the measurement parameters stored at the same
time (a more detailed explanation is found in the Setting Data Storage
Options section of this chapter). The maximum number of samples is 1394.
Test ID:A group of samples. A test ID can contain one sample or up to
1394 samples. The statistics (average, minimum, maximum, and count) are
calculated for each test ID. The maximum number of test IDs is 275.
Time Constant:The time constant is an averaging period. It is used to
dampen the display. If you are experiencing fluctuating flows, a longer time
constant will slow down those fluctuations. The display will update every
second, but the displayed reading will be the average over the last time
constant period. For example, if the time constant is 10 seconds, the display
will update every second, but the displayed reading will be the average from
the last 10 seconds. This is also referred to as a “moving average”.
Logging Interval:The logging interval is a frequency period that the
instrument will log readings. For example, if the logging interval is set to 30
minutes, readings will be taken and recorded every 30 minutes.
ON/OFF Key
Press to turn the VELOCICALC Plus on and off. During the power up
sequence the display will show the following: all characters, % battery life,
% log (memory available), baud rate, time (HH:MM), entered barometric
pressure, entered temperature, and then velocity readings.

8 Chapter 3
Arrow () Keys
Press to scroll through choices while setting a parameter.
ENTER Key
Press to accept a value or condition.
Backlight Switch
Slide the switch in the upward position to turn on the backlight. The
backlight switch is marked in the international symbols ‘|’ for on and ‘O’ for
off. The backlight will remain on until switched off.
VELOCITY/FLOWRATE Key
Press to toggle back and forth between displaying velocity and flow rate. In
flow rate mode, there are 3 options: flow rate from velocity and area, flow
rate from velocity and a horn, and flow rate from pressure and a K factor.
These are indicated by circle, rectangle, horn symbol and pressure units. Use
 keys to scroll through and select the desired symbol, then press ENTER
to accept the choice. To change the flow rate mode, press either the or 
key while displaying flow rate, use the  keys to make your selection,
then press ENTER to accept the choice. The test ID will automatically
increment to the next test ID if flow data has previously been stored in the
current test ID.
•If circle is chosen:
SIZE will flash on display. Use  keys to select size (diameter), then
press ENTER to accept the choice and return to measuring.
•If rectangle is chosen:
X SIZE will flash on display. Use  keys to select the x-size of the
duct, then press ENTER to accept the choice and advance to the next
dimension. Y SIZE will flash on display. Use  keys to select the y-
size of the duct, then press ENTER to accept the choice and return to
measuring.
•If horn symbol is chosen:
Use  to scroll through horn numbers shown on the display (100,
300, 600, 1200) and Kfsymbol, then press ENTER to accept the choice.
NOTE: The horn numbers are the models of the horns. For example,
100 refers to a horn model number AM 100. Only horns with Model
numbers as follows can be used with this function: AM 100, AM 300,
AM 600 and AM 1200. If a horn model number is chosen, the
instrument will return to measuring mode and use a preprogrammed
curve to calculate flow rate from velocity. If Kfis chosen, the K factor
choices will be shown in the following order: last 5 values used, then a

Operation 9
new value which can be adjusted from 0.01 to 999.9. Use the  to
scroll through the Kfchoices, then press ENTER to accept the choice.
NOTE: This measurement can only be made with the thermal
anemometer sensor, not the Pitot tube.
•If pressure units (in H2O, mm Hg, Pa, hPa, or mm H2O) are chosen:
Use  keys to select the K factor, then press ENTER to accept the
choice. The K factor choices will be shown in the following order: last 5
values used, then a new value which can be adjusted from 0.01 to 999.9.
You can zero the pressure while in flow rate from pressure mode by
pressing and holding the pressure key for three seconds. The unit will
double beep to confirm that the pressure has been zeroed. NOTE: This
measurement method is intended for use with diffusers with pressure
taps and a manufacturer-supplied K factor.
When measuring velocity or flow rate, and the measurement type is
changed, the next time the VELOCITY/FLOWRATE key is pressed, the last
measurement used will be displayed. For example, if you were measuring
flow rate, switched to measuring humidity, and then back to VELOCITY/
FLOWRATE, the VELOCICALC Plus will go back to displaying flow rate. If
you were measuring velocity, then humidity, and returned to VELOCITY/
FLOWRATE, the instrument will return to velocity.
PRESSURE (zero) Key (Models 8385/8385A/8386/8386A Only)
Press and release to display pressure. Press and hold for three seconds to
zero the pressure reading. The unit will double beep to confirm that the
pressure has been zeroed. NOTE: Make sure that all tubing is disconnected
or open to ambient conditions before zeroing.
TEMPERATURE Key
Press and release to display temperature on the large digits instead of
showing it on the small digits. Temperature is usually displayed on the small
digits when other measurement types are on the large digits.
NOTE: For temperature and humidity measurements, make sure that at
least 3 inches (7.5 cm) of the probe is in the flow to allow the temperature
and humidity sensors to be in the air stream.

10 Chapter 3
HUMIDITY Key (Model 8386/8386A Only)
Press to toggle between displaying % relative humidity, dew point
temperature, and wet bulb temperature on the large digits. (The first time
that the button is pushed it will display the last measurement type that was
displayed.) NOTE: To display accurate wet bulb temperature, the correct
barometric pressure must be entered. See Actual/Standard Key section for
details on setting the barometric pressure. NOTE: For temperature and
humidity measurements, make sure that at least 3 inches (7.5 cm) of the
probe is in the flow to allow the temperature and humidity sensors to be in
the air stream.
THERMAL/PITOT Key (Models 8385/8385A/8386/8386A Only)
Press to toggle back and forth between measuring velocity or flow rate with
the thermal anemometer sensor or with a Pitot tube attached to the pressure
ports. NOTE:If this key is pressed while displaying anything other than
velocity or flowrate, it will have no effect on the readings.
ACTUAL/STANDARD Key
Press to toggle between displaying actual and standard velocity or flow rate.
Press and hold to view, enter, or change ambient conditions. When the key is
pressed and held, the pressure units will flash and the last barometric
pressure entered will be displayed. Use the  keys to change the
barometric pressure and press ENTER to accept it. Then the temperature units
will flash and the last temperature entered will be displayed. Use the 
keys to change the temperature and press ENTER to accept it and return to
measuring mode. The ranges that can be entered are as follows: Pressure: 15
to 40 in. Hg (381 to 1016 mm Hg), 29.92 in. Hg (760 mm Hg) is default;
Temperature: -80 to 400°F (-62 to 204°C), 70°F (21.1°C) is default. NOTE:
When obtaining wet bulb temperature or heat flow readings, the correct
barometric pressure must be entered. Both the barometric pressure and
temperature need to be entered when measuring the following: 1) actual
velocity (or flow rate) with either the thermal anemometer or the Pitot tube,
or 2) standard velocity (or flow rate) with a Pitot tube.
SAMPLE INTERVAL Key
The SAMPLE INTERVAL key is used to set the time constant and logging
intervals. Press to display current time constant. Use  to scroll through
the time constant choices, which are 1 s, 2 s, 5 s, 10 s, 15 s, 20 s, and LOG
symbol, then press ENTER to accept the choice. If LOG was chosen, the
first logging interval choice will be displayed. Use  to scroll through the
logging interval choices, which are 2 s, 5 s, 10 s, 15 s, 20 s, 30 s, 1 min, 2
min, 5 min, 10 min, 15 min, 20 min, 30 min, 60 min, and OFF. Press
ENTER to accept choice and return to measuring mode. If a logging interval
is chosen that is shorter than the time constant, the time constant will be
shortened to be equal to the logging interval.

Operation 11
NOTE: To operate the instrument in discrete data logging (or single point)
mode, the logging interval must be set to OFF. To operate the instrument in
continuous data logging mode, the logging interval must be set to something
other than OFF.
SAMPLE (options) Key
Discrete Data Logging (Single Point Measurements)
The instrument must first be in discrete data logging mode. See SAMPLE
INTERVAL Key section for more details. Press the SAMPLE key to take a
sample. The sample that gets stored is the measurement types that were
chosen in sample options (see Setting Data Storage Options for more
details) and the measurement type that is on the large digits. While the
sample is being taken, the small digits will read the sample number, the
COUNT indicator will be lit, and the SAMPLE indicator will flash
during the length of the sample. The sample will last until the length of
a time constant has passed. Then the VELOCICALC Plus will display the
sample number and the value that was recorded.
Continuous Data Logging (Multiple Readings Over Time)
The instrument must first be in continuous data logging mode. See
SAMPLE INTERVAL Key section for more details. Press the SAMPLE key
to start a sample. The parameters that are stored are those that were
turned on in the options menu as well as that on the large digits.
Samples will be taken at intervals that were set in the SAMPLE INTERVAL
menu (see the SAMPLE INTERVAL Key section for more details). The
display will light LOG while samples are being taken and SAMPLE will
light as the data is stored. Press the SAMPLE key again to stop the
sample. The display will then scroll through the following: number of
samples stored, test ID number and average of the measurements that
were stored. To review this data and/or individual data points, please
see STATISTICS (review data) Key section.
Setting Data Storage Options
In this section the terms “On” and “AUtO” are referred to. The
following brief explanations may help to understand what function is
being performed. “On” means that measurement type will log whenever
the SAMPLE key is pressed. “AUtO” means that measurement type will
automatically log if it is needed to calculate the measurement type on
the large digits when the SAMPLE key is pressed.
For example, if dew point is being displayed on the large display digits
and SAMPLE is pressed, then dew point, humidity, and temperature will
all be stored automatically because dew point is calculated using

12 Chapter 3
humidity and temperature. Table 3.1 shows what measurements are
stored automatically when a specific measurement type is on the
display.
Table 3.1: Measurement Types Stored When SAMPLE is Pressed
Displayed Measurement
Type
Measurement Types Automatically
Stored
Thermal Velocity
Velocity
Pitot Velocity
Velocity, Pressure
Temperature
Temperature
Pressure
Pressure
Humidity
Humidity
Wetbulb
Humidity, Temperature, Wetbulb
Dew point
Humidity, Temperature, Dew point
Heat flow Heat flow, Humidity, Temperature
(Flow rate is needed, but must be
stored separately)
Flow rate from duct size
and shape
Velocity, Flow rate, Pressure if velocity
is from Pitot
Flow rate from a horn
Velocity, Flow rate
Flow rate from Pressure
Pressure, Flow rate
Press and hold the SAMPLE key to view, enter, or change data storage
options. “SET” lights up on the small display. The velocity units light
up, and the large display says “On” or “AUtO”, depending on how it
was set previously. Use  to toggle between on and auto, then press
ENTER to accept setting and advance to next parameter. The flow rate
units light up, and lower display says “On” or “AUtO”, depending on
how it was set previously. Use  to toggle between on and off, then
press ENTER to accept setting and advance to next measurement. This
pattern will continue through the following measurements: differential
pressure, temperature, relative humidity, dew point temperature, and
wet bulb temperature. Follow the same instructions as set forth above
for each parameter. Once all the measurement parameters have been
displayed, the instrument will return to measurement mode.

Operation 13
NEXT TEST (clear) Key
Press to advance to the next test ID. If the current test ID does not have
anything stored, it will not advance to the next test ID. To clear the last
sample, press and hold the key and the display will begin a countdown from
5 to 0. Release the key at any time during the countdown before zero is
displayed. To clear all memory, keep holding key during the countdown.
Release the key when 0 is displayed. The display will flash ‘CLEAR LOG’.
NOTE: Only the last sample recorded can be cleared without clearing the
entire memory. You cannot go back to a previous test ID and clear a single
reading. Also, you cannot add data to a previous test ID. Sample clear does
not work in continuous data logging mode.
STATISTICS (review data) Key
The STATISTICS key has two purposes. One is to view the statistics for the
currently displayed parameter and the other is review data for a particular
test ID.
To View Statistics
Press STATISTICS to view statistics for the parameter currently shown
on the large digits. The count will be shown on the small digits and the
test ID on the large digits. Count will stay on the small digits and the
large digits will change to displaying average. Press STATISTICS again
(before the average disappears from the display) to proceed to
maximum and again to display minimum.
To Review Data
Press and hold STATISTICS. The VELOCICALC Plus will beep twice,
release the key and the test ID number will be displayed on the small
digits and the TEST ID symbol will light up. Use  to select the
desired test ID. Press ENTER to accept the test ID number. Use  to
select and view average, maximum, minimum, count, and individual
sample numbers with values for the selected test ID. The samples will
be displayed in the order that they were taken, from the first sample of
that test ID to the last. To view a different test ID, press STATISTICS
again to return to test ID on small digits and nothing on large digits. Use
 to choose a new test ID, then press ENTER to accept the choice and
continue as above to review the data. To review data of a different
measurement type, press the desired measurement type button while
AVG, MAX, MIN, COUNT or sample is being displayed. If there is no
data for that measurement type, “----” will be displayed. Press another
measurement type key to view more data or press ENTER to return to
measuring mode.

14 Chapter 3
HEAT FLOW Key (Model 8386/8386A Only)
In order for the VELOCICALC Plus to calculate heat flow, the flow rate,
temperature, and humidity need to be recorded at one location before the
heating (or cooling) source and one location after the source. The data at
these locations must be stored in two sequential test IDs. The first test ID is
used as reference for calculating heat flow in the second test ID. To store the
required data for heat flow calculations, proceed as outlined below.
1. Make sure that the correct barometric pressure is entered in the
instrument or the obtained readings will be incorrect. If flow is being
measured from a Pitot tube, make sure the correct flow temperature is
also entered. The flow rate displayed must be is STANDARD flow, not
ACTUAL flow, or the “nO rEF” message will appear on the display.
This message indicates that there is missing or incorrect reference data
for calculating heat flow. (See ACTUAL/STANDARD Key section for
details on setting these parameters.)
2. Make sure the instrument is in discrete (or single point) sampling mode.
(See SAMPLE INTERVAL Key and SAMPLE (options) Key sections for
details on how to be in discrete sampling mode.)
3. Press NEXT TEST to start a new test ID.
4. Press VELOCITY/FLOWRATE key to display flowrate.
5. Press SAMPLE key and store multiple readings at the first (reference)
location. Taking several samples in the traverse of the duct provides
accurate average readings.
6. Press TEMPERATURE key.
7. Press SAMPLE to record the temperature readings.
8. Press HUMIDITY key to display relative humidity (% RH).
9. Press SAMPLE to record the relative humidity.
10. Press NEXT TEST key to advance to the next test ID. Move probe to the
second location. (Make sure that at least 3 inches (7.5 cm) of the probe
are in the flow to allow the temperature and humidity sensors to be in
the air stream.)
11. Press HEAT FLOW key to get instantaneous readings of sensible heat
flow. Press key three more times to display latent heat flow, total heat
flow, and sensible heat factor.
12. Press SAMPLE key to store readings at second location.