Furnace draft transmitter range is -50 to +50 mmwc. why the
impulse line connected in hp side?
Answer Posted / carl_ellis
A draft range measurement is typically a gauge pressure
measurement, referenced to atmosphere.
Draft range is very, very low pressure, so DP transmitters
are typically used because they're readily available in
a 'draft' range with the large diaphragms necessary for low
pressure measurements.
The high side is connected to the process with an impulse
tube. The low side is exposed to atmospheric pressure.
Good practice puts a filter, like a scintered pneumatics
filter on the low side, so that dirt doesn't fill the low
side cavity and air movement (wind, passing vehicles) is
buffered and damped to prevent the forces of air movement
on the low side from affecting the draft measurement.
If the impulse line were connected to the low side, the DP
would be negative, a DP subtracts the low side pressure
from the high side pressure (atmosphere minus some positive
pressure = negative pressure). Convention says that draft
range is positive so the impulse connection is to the high
side, to get a positive value.
Tell 'em Carl sent you.
Is This Answer Correct ? | 12 Yes | 1 No |
Post New Answer View All Answers
what deference between panel earth and systemearth
What is standard of DCS panel design?and what is step of DCS panel design?wiring and type of connector(screw or DB connector)
Instrumentation Safe Guarding test. How to determine the interval time of the test. eg:Halfyearly,Every year,Every three years etc.
Derive capacitance to 4-20ma conversion formula / relation in capacitance type pressure sensor?
Which Signal hart communicator work? If there any signal change when hart connect while transmitter in line ?
what is your eligibility criteria for freashers?
In turbine, what does term CDP, NI, NH, HSSOC, means
whatis range of marcury filled tempereture gague
how to calibrate 0- 150 psi presure gauge by dead weght tester
How to Calibrate Flammable gas detector in field
Name different parts of a pressure gauge.
Do you have reference list?
HI friends.I am Surya a BTech in Electronics and Instrumentation Engineering.I am going to appear Relince Industries Ltd all India writen test very soon. so plz help me by sendind the probable questions about my subject.My mail ID is surya.barik@gmail.com.
when the instrument tapping on pipe line is located below and transmitter is located above the tapping point for liquid service transmitter, what should we do, is there any additional drain valve is required??
what is the reset offset and control system in instrumentation