Appendix C -Analog Voltage Outputs - Omega HHF142 User Manual

APPENDIX C -ANALOG VOLTAGE OUTPUTS

If the instrument is equipped with the analog output option, there will be a five­
pin connector on the bottom of the instrument. Also, an analog output cable will
be included with the instrument. This cable will have a five-pin connector on
one end and four tinned wires on the other end.
The instrument will output a Voltage between O and 5 Volts that corresponds to
the Air Velocity measured by the instrument. The output range, pin
assignments, and wire colors are given in the table below. Also shown is a
block diagram of the analog output circuit.
Wire
Color Pin#
BLK
2
GRN
GRY 3
WHT
4
*To convert from Volts to Air Velocity in Feet per Minute, multiply by 2000.
►
For example, an analog output of2.375 Volts means that the instrument is
measuring an air velocity of 4750 feet per minute (FPM).
►
2.375 Volts
x
Note:
When using analog outputs, there is an
analog output voltage. This is in addition to the normal measurement error.
►
For example, an air velocity reading of 500 FPM would normally have an
accuracy of± 1 % of reading ± 1 digit ( ± 6 FPM) when the data is viewed
on the LCD display.
► With the additional error associated with the analog output voltage, the
effective accuracy of the analog output for this air velocity measurement
will be ±2% of reading ±1 digit (±11 FPM).
Custom Analog Voltage Outputs are also available - contact Omega for details.
(IF EQUIPPED)
Corresponding
Analog Output
Measurement
2000 = 4750 FPM
Equation* to convert from
additional ±1 error
% in the
Rev 1.9, 10-Jun-2008
Page 15 of28