Dwyer VTT - Manual (Page 2)

©Copyright 2010 Dwyer Instruments, Inc. Printed in U.S.A. 6/10 FR# R1-443704-00 Rev. 1
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000 www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: 219/872-9057 e-mail: [email protected]
4-20 mA MODEL (4-Wire)
passive input
4-20 mA MODEL (3-Wire)
TRANSMITTER SETUP
To configure the Series VTT, unscrew the two screws on the housing of the
transmitter, and remove the cover to reveal the DIP switches.
These DIP switches are used to control the units and ranges of the temperature
and air velocity of the transmitter as shown below.
Please Note: Before attempting to alter the DIP switch settings, ensure that the
transmitter is not powered.
Configurations 32 to 122°F
1 2 3 4
-4 to 176°F
1 2 3 4
-58 to 122°F
1 2 3 4
32 to 212°F
1 2 3 4
Configurations 0 to 50°C
1 2 3 4
-20 to 80°C
1 2 3 4
-50 to 50°C
1 2 3 4
0 to 100°C
1 2 3 4
Field Selectable Temperature Ranges
MAINTENANCE
In general the Series VTT should require very little maintenance. In some
installations dust may accumulate on the sensor over time. This can be removed
by carefully brushing the probe with a small camel hairbrush. If too much force is
applied during cleaning, the sensor of the Series VTT may be damaged. Therefore,
a trained technician should perform the cleaning operation. A jet of air may also
dislodge the accumulated buildup however, again, the sensor is delicate and this
operation should be done carefully with clean regulated air. Using a shop air supply
may exert enough force to damage the sensor. Most air supplies of this sort will
also contain water or oil that could damage the sensor. Technical grade denatured
or isopropyl alcohol may be used where the dust accumulation does not respond
to brushing. Do not use water. Always disconnect the power when performing a
cleaning operation. With the above exceptions, these items are not field repairable
and should be returned to Dwyer Instruments, Inc. for repair. Please contact a
customer service representative for a return goods authorization.
0-10V MODEL (3-Wire)
ELECTRICAL CONNECTIONS
0-10V MODEL (4-Wire)
Configurations 0 to 1000 fpm 0 to 2000 fpm 0 to 3000 fpm 0 to 4000 fpm 0 to 6000 fpm
0 to 5 m/s 0 to 10 m/s 0 to 15 m/s 0 to 20 m/s 0 to 30 m/s Configurations
1
2
3
4 1
2
3
4 1
2
3
4 1
2
3
4 1
2
3
4
1
2
3
4 1
2
3
4 1
2
3
4 1
2
3
4 1
2
3
4
Field Selectable Velocity Ranges
Note: The standard temperature range should be 0-50°C or 32-122°F. If you select
a different temperature setting, the air velocity may not operate outside the
performance range shown in the velocity range versus temperature diagram
below.
air velocity
maximum possible
measurements ranges
based on working
temperatures
temperature
0°C 10°C 20°C 30°C 50°C 40°C
V max. f(T°)
30 m/s
25 m/s
20 m/s
15 m/s
10 m/s
5 m/s
AV-3-VTT:TEMPLATE 6/1/10 1:25 PM Page 2