Industrial Transmitters

1. INDUSTRIAL TRANSMITTERS
PRESENTED TO:
ENGINEERING DEPT. SEPL.
PRESENTED BY:
MUHAMMAD FAIZAN SALEEM
Presentation # 3
1/7/2016
1

2. CONTENTS
 Sensor
 Transducer
 Transmitter
 Types of transmitter
 Applications of Transmitters
1/7/2016
2

3. SENSOR
 A sensor is an object whose purpose is to detect
events or changes in its environment, and then
provide a corresponding output.
 Primary element.
 Examples: Human body, Hall effect sensor etc.
1/7/2016
3

4. TRANSDUCER
 A transducer is a device that receives a signal and
converts it in a different form(Readable for devices).
For example, I/P transducers that convert a current
signal to pneumatic form.
 Also thermocouple represents a temperature
change as a voltage change.
1/7/2016
4

5. TRANSDUCER TYPES
 Active Transducer(e.g. TC , Piezoelectric
accelerometer)
• Do not require any input power for operation.
 Passive Transducer(e.g. LDR,RTD)
• Require input power for operation
1/7/2016
5

6. RTD VS. THERMOCOUPLE
1/7/2016
6

7. ADV. & DISADV. OF RTD AND TC
1/7/2016
7

8. TRANSMITTERS
 A set of equipment used to generate and transmit
electromagnetic waves carrying messages or
signals.
 A transmitter which we deals with usually converts the
sensor output to a signal level appropriate for input to a
controller, such as 4 to 20 mA.
 It is secondary element.
 Transmitters are generally designed to be direct acting.
 Mostly transmitters have an adjustable input range.
 For example, input range of a platinum resistance
element (the sensor) is 50 to 150 °C.
1/7/2016
8

9. TRANSMITTER TYPES
 Pressure Transmitter
 Temperature Transmitter
 Flow Transmitter
 Level Transmitter
1/7/2016
9

10. PRESSURE TRANSMITTER
 A pressure transmitter is a device that measures
pressure in a liquid, fluid, or gas.
 It generates a signal as a function of
the pressure imposed.
 There are three kinds of pressure transmitters.
1/7/2016
10

11. TYPES
i. Absolute Pressure Transmitters
• Pressure measured relative to perfect vacuum.
ii. Differential Pressure Transmitters
• Pressures of two distinct positions are compared.
iii. Gauge Pressure Transmitters
• Subtype of differential pressure measurement where
we compare pressure at any point to the current
atmospheric pressure
1/7/2016
11

12. 1/7/2016
12

13. PRESSURE TRANSMITTER WIRE
CONFIGURATION
 Two Wire Transmitter(loop powered instruments)
 In two wire system, the only source of power to
transmitter is from the single loop.
1/7/2016
13

14. CONTINUE..
 Three wire transmitter
 Some instruments require more power than single loop.
DC common wire is run from the instrument to the
transmitter.
1/7/2016
14

15. CONTINUE..
 Four Wire Transmitter(self-powered instruments)
 They require no connection to DC power supply.
1/7/2016
15

16. APPLICATIONS
 Touch Screen Devices
 Automotive Industry
 Aviation
 Marine Industry
 Industrial Uses
1/7/2016
16

17. TEMPERATURE TRANSMITTER
 A temperature transmitter is an electrical instrument
that interfaces a temperature sensor (e.g.
thermocouple, RTD, or thermistor) to a
measurement or control device (e.g. PLC, DCS, PC
etc.).
 It is used to convert a temperature sensor’s low-
level (ohm or mV) signal to a standard 4-20mA
current signal that can be readily accepted by a
monitoring and control system, such as a DCS or
PLC.
1/7/2016
17

18. WORKING PRINCIPLE
 Two wire transmitter accepts input from a
thermocouple or three wire pt100 and converts the
output into 4-20mA current signal.
1/7/2016
18

19. USES OF TEMPERATURE TRANSMITTER
 The signals generated by Resistance Temperature
Detector or Thermocouple are categorized as low-
level signal hence it has more noise immunity.
 No need to provide special I/O card for
thermocouple/RTD. Just connect the Transmitter to
the Analog I/O card.
 Provided maintenance facilities such as diagnostic
feature in smart transmitter.
1/7/2016
19

20. FLOW TRANSMITTER
 Flow transmitters are an integral tool for measuring
the flow of liquid, gas, or a mixture of both.
 There are following types of flow transmitters:
 Differential-pressure flow meter
 Electromagnetic flow meter (magmeter)
 Ultrasonic flow meter
1/7/2016
20

21. DIFFERENTIAL-PRESSURE FLOW METER
 It measures the differential-pressure drop across a
constriction in the flow’s path to get the flow
velocity.
 Measuring this differential pressure gives a direct
measure of the flow velocity from which the
volumetric flow can easily be calculated.
1/7/2016
21

22. ELECTROMAGNETIC FLOW METER
(MAGMETER)
 It is based on Faraday’s Law of electromagnetism.
1/7/2016
22

23. ULTRASONIC FLOW METER
 Doppler-shift meter(Can not measure extremely
clean liquids)
 Transit-time meter
1/7/2016
23

24. APPLICATIONS
 Food and beverage industry.
 Oil and gas plants.
 Chemical/pharmaceutical factories
1/7/2016
24

25. LEVEL TRANSMITTERS
 A Level Transmitter is simply an instrument that
provides continuous level measurement.
 Level transmitters transmit a particular output signal
that is ideally compatible with a corresponding
sensor and meter/indicator in a given application.
Common outputs include:
 Current loops
 Fieldbus protocols
 Frequency signals
1/7/2016
25

26. TYPES OF LEVEL TRANSMITTER
 Capacitance
 Pressure
 Radar
 Ultrasonic
1/7/2016
26

27. CAPACITANCE LEVEL TRANSMITTER
 In this transmitter capacitance of capacitor is
changed w.r.t. level.
1/7/2016
27

28. PRESSURE LEVEL TRANSMITTER
 Pressure sensor is placed at the bottom and gives
output with respect to the pressure applied.
1/7/2016
28

29. RADAR LEVEL TRANSMITTER
 Emits high frequency radar pulses from the antenna
and reflected from the product surface.
1/7/2016
29

30. ULTRASONIC LEVEL TRANSMITTER
 Measures time between emission and reflection of
acoustic signals to determine level.
1/7/2016
30

31. 1/7/2016
31