Temperature Sensor
Temperature Sensor
Temperature Sensor
For this process, we have chosen feedback control loop as our primary control element. There
are two heat exchangers which are E-301 and E-302.Both heat exchanger are design to
control the outlet temperature and the pressure from the heat exchanger. Feedback control
system has few advantages in this case.
i) Accuracy: They are more accurate than open loop system due to their
complex construction. They are equally accurate and are not disturbed in
the presence of non-linearity.
ii) Noise reduction ability: Since they are composed of a feedback
mechanism, so they clear out the errors between input and output signals,
and hence remain unaffected to the external noise sources.
Valve 1
RTD is works on the measurement principle that a materials electrical resistance varies with
temperature. The relationship between an RTDs resistance and the surrounding temperature
is highly predictable, allowing for accurate and consistent temperature measurement.
Supplying an RTD with a constant current and measuring the resulting voltage drop across
the resistor, the RTDs resistance can be calculated, and the temperature can be determined.
In this RTD, the change in resistance value is very small with respect to the temperature. So,
the RTD value is measured by using a bridge circuit.
Electronic pressure sensor with analogue display. Suitable for all standard processes.
Analogue display 0 to 350 rotatable, resolution 0.25%.Pointer not visible when unit
disconnected, no dead space, 4-digit alphanumeric display, 2 outputs, OUT1 = switching
output, OUT2 = analogue output, Ambient temperature range from -25 to 80 C, Measuring
range from 1 to25 bar. Since our heat exchanger operates at very high temperature, this
pressure sensor has many advantages.
Reference
1. http://www.123mylist.com/2012/01/open-closed-loop-system-advantages.html
2. http://www.azom.com/article.aspx?ArticleID=5573
3. http://www.preferred-mfg.com/products/pi/Steam-Pressure-Transmitter
4. http://www.ifm.com/ifmuk/web/apps-by-industry/pressure-measurement-on-a-heat-
exchanger.html