1. How to write the program for single push button by using Ladder diagram?
1. Create a Push button
2. Connect a Counter series to PB
3. Create a compare button
4. Initialize 1 at one end
5. Counter output in another
6. Connect the Coil which has to be energized
7. Initialize 2 at one end
8. Counter output in another
9. Connect the Coil which has to be reenergized.
Remote mount with MTA means MTA connector for mounting remote connection.
MTA is the Connector used for connection. Generally we called it MTA Connector.
There are many types of MTA connector such as MTA 100connectors, Mta 156 connectors etc...
3. Why 4-20 mA signal is preferred over a 0-10V signal?
Generally in a transistor some amount of voltage is required for turning it on. This voltage is the cut in voltage. Up to this voltage the exists a nonlinearity in its characteristics. Beyond this cut in voltage the char. of transistor is linear. This nonlinear region lays between 0-4ma, beyond 4ma it linear. This is why 4-20 ma range is used.
4. Can we use a control valve without positioner?
Control valve can not be without positioner. The purpose of the positioner is to control the control valve stroke so as to keep the valve in desired position. The positioner receives signal from the controller, and send the boosted signal to the actuator to reach the desired position as and when the valve reaches the desired position the positioner cuts the boosted signal to the actuator and keeps the position.
5. What is Instrumentation Measurement?
Instrumentation can be used to measure certain field parameters (physical values):
These measured values include:
* pressure, either differential or static
* flow
* temperature - Temperature_measurement
* level - Level Measurement
* density
* viscosity
* radiation
* current
* voltage
* inductance
* capacitance
* frequency
* resistivity
* conductivity
* chemical composition
* chemical properties
* various physical properties
6. What is Instrumentation Control?
In addition to measuring field parameters, instrumentation is also responsible for providing the ability to modify some field parameters.
Some examples include:
Device Field Parameter(s)
Valve Flow, Pressure
Relay Voltage, Current
Solenoid Physical Location, Level
Circuit breaker Voltage, Current
7. What is Instrumentation Instrumentation engineering?
Instrumentation engineering is the engineering specialization focused on the principle and operation of measuring instruments which are used in design and configuration of automated systems in electrical, pneumatic domains etc. They typically work for industries with automated processes, such as chemical or manufacturing plants, with the goal of improving system productivity, reliability, safety, optimization and stability.
8. What is Instrumentation technologists and mechanics?
Instrumentation technologists, technicians and mechanics specialize in troubleshooting and repairing instruments and instrumentation systems. This trade is so intertwined with electricians, pipefitters, power engineers, and engineering companies, that one can find him/herself in extremely diverse working situations. An over-arching term, "Instrument Fitter" is often used to describe people in this field, regardless of any specialization. oo nga.
9. Difference between DCS and PLC including date processing and architecture.
If we have more I/o's in digital signals than analogue signals normally we choose DCS....and vice versa.
11. How to use control and instrumentation terminology and its correct context on circuit breakers?
No idea...
need answer of this question plz share if any one knows how to use control and instrumentation terminology
Thanks in advance....
12. Why we giving input to electronic amplifier in inverting pin? what is the reason behind that?
if we need a phase shift than we give input n inverting pin or when we need to boost signal at higher level, i.e; using cascade stages of amplification(even) than we also use inverting pin
13. What is the function of 3-way manifold valve?
excessive pressure to your differential pressure transmitter, you could damage your instrument. This is known as over-ranging the transmitter.
A three-way manifold valve is a device that prevents the instrument from being over-ranged. It also allows the isolation of the transmitter from the process loop (an option which could be used generaly for maintenance or re-calibration or fitting new equipment).
14. Why we are using resistance with limit switch?
why we are using line monitoring in limit switch?
if some one knows answer please send me on this mail ( mudi_inst [at] yahoo [dot] com)
thanks
15. Do you know How D.P. transmitter can be applied to close tank?
In closed tank, bottom of the tank is connected to the high pressure side of the transmitter. Top of tank is connected to the lower pressure side of the transmitter. In this way vessel pressure can be measured.
16. Explain How D.P. transmitter can be applied to open tank?
In open tank the lower pressure side is vented to the atmosphere. All pressure is applied to the high pressure side. This vessel pressure is measured through high pressure side.
17. Do you know the working of an electronic level troll?
The variation in level of buoyancy resulting from a change in liquid level varies the net weight of the displacer increasing or decreasing the load on the torque arm. This change is directly proportional to change in level and specific gravity of the liquid. The resulting torque tube movement varies the angular motion of the rotor in RVDT providing a rotor change proportional to the rotor displacement, which is converted and amplified to a D.C. current.
18. Tell me the working of an enraf level gauge?
Enraf level gauge is based on the ser powered null balance technique. A displacer serves as continuous level sensing element. A two phase ser motor controlled by a capacitive balance system winds unwinds the the measuring wire until the tension in the weight springs is in balance with the weight of the displaced part immersed in the liquid. The sensing system in balance measures the two capacitance formed by the moving central sensing rod provided by the two capacitor plates and the si plates.
19. What is constant voltage unit?
The constant voltage circuit consists of a rectifier, CR and a filter capacitor. It is followed by two stages of zener regulation. Abridge configuration is provided to lamp line voltage zener regulation. Regulation 1 and regulation 2 provides relatively provide constant current. Resistors form a bridge that may remoment line voltage effects.
20. Can you explain the burnout feature?
Burnout provides the warnsug feature of driving indicator at the end of scale, if the input circuit is open. A burnout resistor is provided which develops a voltage drop between the measuring circuit and amplifier. The polarity of the signal determines the direction of the servo drive upon an open circuit in the input.
Upscale burnout: R value 10 M
Downscale burnout: R value 22 M
21. Why thermo wells are used? What materials are used in thermo wells?
In numerous applications, it is neither desirable nor practical to expose a temperature sensor directly to a material. Wells are therefore used to protect against damage corresion, arosion, aborsion and high pressure processes. A thermo well is also useful in protecting a sensor from physical damage during handling and normal operations.
Materials used in thermo wells: Stainless steel, Inconel, Monel, Alloy Steel, Hastelloy
22. List of Instrumentation Engineering Job Interview Questions!
1. How can leveltrol be installed in steam drum for measuring the level of steam drum?
2. What is ultrasonic flowmeter?
3. Differentiate between ultrasonic flowmeter and radar type flow meter.
4. What is the use of temprature compensation?
5. What is modbus?
6. How signals can be taken through modbus?
7. How earthing can be checked?
8. How many ohms are required for proper earthing?
9. Explain signal isolator.
10. Which wiring connection is preferred in motor for industrial use?
11. What do you mean by trim?
12. How DP Transmitter can be calibrated for crude application in floating roof tank?
13. What is the principle of capacitance type level transmitter?
14. How process line mpm calculation is done?
15. Explain PLC Level and its type?
16. What is procedure on mmwc in to tph?
17. How an rtd work, and what volts/current goes to a RTD to measure the resistance?
18. What is consistency transmitter and describe its working?
19. How to calculate MMWC values into tonnes?
20. How can I make calculation to Install level transmitter (DP) for open tank and close tank?
21. What is difference between DO and DI?
22. What is loop1 and loop2 in MTS LT?
23. How to calibration a control valve?
24. What is dry leg calibration and where is it used?
25. How flow can be measured with dp?
26. Why MMWC unit is used?
27. How HART protocol can be connected with control valves?
28. What is the meaning of slope in PH transmeter?
29. What is Difference between PLC and CNC?
30. If we have 450 mm height boiler drum level, so what is span & zero value for a dpt transmitter?
31. How can level transmitter in closed tank application be used?
32. Why ac supply load cell is used? Can we use the dc supply load cell?
33. What are advantages and disadvantage of the ac supply load cell?
34. What is coriolis principle for mass flow meter?
35. What are the automatic controller MODES?
36. What is Cryogenic?
37. What happen if we install my pressure transmitter below the elevation of pipe in natural gas service?
38. What are the reliability data, like failure rate etc, for bently Nevada systems & vibration probes?
39. What is the meaning of wet leg & where is it used?
40. What are the key components of control loop?
41. Working principle of lvdt?
42. What is difference between differential pressure & delta pressure?
43. How to trim the pressure transmitter?
44. What are different types of cable?
45. What is the use of control cable?
46. Which type of diaphragm use in costic line, DM water line, natural gas line, oil line?
47. What are different types of valves?
48. What is the hydra step level sensor output value (measuring level of steam drum)?
49. What is mean by live zero and dead zero?
50. When a magnet is heated?
51. Why the degree of valve plugs and valve seat is slightly different I control valve trim design?
52. What is modbus, profibus, fieldbus?
53. What is the use of gauge?
54. How to calibrate differential pressure switch?
23. Explain What are different types of orifice plates? State their uses?
Different orifice plates are:
1. Concentric
2. Segmental
3. Eccentric
- Concentric: These plates are used for ideal liquid as well as gases and steam service. Concentric holes are present in these plates, thats why it is known as concentric orifice.
- Segmental: This plate has hole in the form of segment of the circle. This plate is used for colloidal and sherry flow measurement.
- Eccentric: This plate has the eccentric holes. This plate is used in viscous and sherry flow measurement.
24. Do you know How do you identify an orifice in the pipeline?
An orifice tab is welded on the orifice plate which extends out of the line giving an indication of the orifice plate.
25. Explain Why is the orifice tab provided?
Following reasons justify for providing orifice tab:
1. Indication of orifice plate in a line
2. The orifice diameter is marked on it.
3. The material of the orifice plate.
4. The tag number of the orifice plate.
5. To mark the inlet of an orifice.
