?’s Flashcards
(29 cards)
Why calibration of instrument is important?
it ensures the accuracy of measurements taken by a device, maintaining consistency in production, and minimizing the risk of safety hazards by preventing inaccurate readings
What are the Process Variables?
Flow, Pressure, Temperature, & Level
Define all the process Variable & state their unit of measurement.
Flow:litters/gallons per minute
Pressure:pounds per square inch (psi)/Pascals
•Level Measurement: meters/inches
Temperature:Celsius, Fahrenheit, Kelvin
How to measure mA output of Transmitter?
Connect multimeter in series with transmitter and putting multimeter in DC MA measuring mode
What are the primary elements used for flow measurement ?
Orifice Plate, Venturitube, Pitot tube,, FlowNozzle,
What are the different types of orifice plates?
1.concentric
2.segmental
3.eccentric
4.quadrant edge
How to remove DPT from Service?
Step-1 Close LP Block Valve
Step-2 Open the Equalizing Valve
Step-3 Close the HP Block Valve
How to Put DPT back into service?
Step-1 Open the Equalizing Valve
Step-2 Open the HP Block Valve
Step-3 Close the Equalizing Valve
Step-4 Open the LP Block Valve
How to identify an orifice in the pipe line?
An orifice tab is welded on the orifice plate which gives indication that orifice plate is in pipe line
What is the purpose of Orifice Tab?
Indication of an orifice plate in a line
The orifice diameter is marked on it
The material of the orifice plate The tag number of the orifice plate
How do you carry out piping for a DPT on liquid services and Why?
DPT is mounted below
Orifice Plate because Liquids has a property of Self Draining
How do you carry out piping for a DPT on Gas services and Why ?
DPT is mounted above the orifice plate because Gases have a property of self venting
How do you carry out piping for a DPT on Steam services ?
DPT is mounted below Orifice with condensation Ports
What is the purpose of Condensation Port?
to collect and remove liquid condensate from a gas or steam line and preventing the sensor to reduce inaccurate readings
What is the Purpose Of Square Root Extractor?
It takes the square root of the signal from the Flow Transmitter& converts a corresponding linear flow signal
What is the working principle of Magnetic Flowmeter?
It measures volumetric flow rate of liquids.
If an operator tells you that flow indication is more, How would you start checking?
Step-1 Flush both the impulse lines.
Step-2 If still the indication is more then Check L.P. side for choke
Step-3 If there is no choke on both side then Check the leaks on L.P side.
Step-4 If still problem, Calibrate the transmitter
What is absolute pressure?
AP is the total pressure present in the system
What is Vacuum Pressure?
Pressure below atmospheric pressure is known as vacuum pressure
What is SMART Transmitter?
-It is a microprocessor based transmitter that sends a 4-20 mA signal and it’s more accurate than older transmitters
What is the difference between 2 wire, 3 Wire & 4 Wire transmitter ?
-2 Wire TX: One common Cable for Power & Signal
-3 Wire TX: 2 wires for signal and power and the third to provide common ground connection.
-4 Wire TX: 2 separate wire for power & 2 separate wire for signal
What is Live Zero, or why 4-20 mA signal is prefered over 0-20 mA signal?
In 4-20 mA signal 4mA represent minimal value & 20mA represent maximum value.
In 4-20 mA: at lower range value, transmitter output would be 4 mA, & if transmitter is faulty or connection break happens then transmitter output would be 0 mA
What are the primary elements for measuring pressure?
- Bourdon Tube
2.Diaphragm - Capsule
- Bellows
5.Pressure Springs
How to connect D.P. transmitter to a Open tank?
For Open Tank: Low Port Side of DPT is vented to Atmosphere
