Teledyne ULTRAFLOW 150, Руководство по эксплуатации, Страница: 16 / 162

ULTRAFLOW 150 GAS FLOW AND TEMPERATURE MONITOR
Table 3-1
Dual Analog Input Board Jumpers for Pressure Input
DESCRIPTION JUMPER
NUMBER
LABEL POSITION WIRING
Barometric Pressure Assembly JU2 Don’t
Care
Don’t Care None
JU3 INT 1-2
4-20mA Pressure Transmitter JU2 CUR 1-2 J4 Terminals
1(+) and 2(-)
JU3 EXT 3-4
0-5VDC Pressure Transmitter JU2 VOL 3-4 J4 Terminals
3(+) and 2(-)
JU3 EXT 3-4
3.3.2 External Temperature Measurement
The Ultraflow 150 can measure medium temperature in two manners:
INTERNAL MEDIUM TEMPERATURE: This measurement uses the
speed of sound data derived from the time of flights between the
upstream and downstream ultrasonic transducers. Since speed of
sound is directly proportional to the square root of absolute
temperature, a temperature measurement can be made based on this
data provided the concentrations of the major constituent gases
(usually O2, CO2, H20 and N2) are either relatively constant or
change predictably as a function of speed of sound. Examples of
applications where this is true include flow monitoring of single fuel
utility boiler stack gas emissions, cement kiln combustion emissions,
secondary combustion air and process steam boiler emissions.
EXTERNAL MEDIUM TEMPERATURE : This measurement utilizes
external, non-ultrasonic sensors to establish medium temperature.
This technique is recommended when the concentrations of the major
constituent gases (usually O2, CO2, H20 and N2) change
unpredictably or are not a function of speed of sound. In these cases,
the absolute values of the Ultraflow 150’s INTERNAL MEDIUM
TEMPERATURE will be inaccurate by magnitudes roughly
proportional to the change in molecular weight. An example of such an
application is a multi-fuel (i.e., one that can run on coal or natural gas
at base load) utility boiler.
The Dual Analog Input Board option is required to implement the
EXTERNAL MEDIUM TEMPERATURE option. The Dual Analog
Input Board is compatible with a variety of external temperature sensors:
1000 ohm 2 wire RTD’s (see the next sub-section of this manual), 4 – 20
mA and 0 to 5 Volt. Thermocouples are not supported. See the System
Properties Menu section (Section 6.0) of this manual for information on
calibration of EXTERNAL MEDIUM TEMPERATURE devices.
3-3