This document provides information on the skills and responsibilities of an Instrument Technician. It discusses that an Instrument Technician is responsible for calibrating process instruments in the field and bench. They also have skills in troubleshooting, testing loops, and commissioning process equipment. The document then lists various skills and knowledge required, including calibrating different types of instruments, installing tubing and instruments, understanding diagrams, and ensuring safety practices.

2. • is a skilled person whose responsible for
bench and field calibration of different kinds
of process instruments.
• Had a proven skills also in termination,
troubleshooting, loop testing, pre-
commissioning, commissioning, building
automation and process equipment
monitoring.

3. Instrument Technician must have skills and
knowledge in:
• Bench/Field calibration of process
instruments
• Bending and installation of
stainless/copper tubing
• Leak testing of process tubing
• Mounting and installation of different kinds
of process instruments

4. • Basic principles of process instruments and
devices
• Basic logic symbols and schematic diagrams.
• System logic testing, complex loops and
interlocking system associated with the PLC.
• Process instrumentation diagrams.
• Instrument and accessories installation
procedure.
Instrument Technician must have skills and
knowledge in:

5. Instrument Technician must have skills and
knowledge in:
• Local and DCS panels, field junction box
installation procedure
• Linear measurements in both English and
Metric System
• Identification of different kinds, type and
size of instrumentation materials like
fittings, tubing, piping, etc.

6. Instrument Technician must have skills and
knowledge in:
• Material take-off and estimate
• Basic rigging technique and scaffolding
installation
• Proper use and operation of tools and
equipments
• Safety practices and housekeeping

7. • A device used directly or indirectly to measure
and/ or control a variable.
• The term includes primary elements, final
control elements, computing devices and
electrical devices such as switches and
pushbuttons.
• a collection of instruments or their applications
for the purpose of observation, measurement
and control. (ISA Definition)

8. HISTORY OF INSTRUMENTATION
• More than two centuries has already
passed since Oliver Evans used
feedback control to automate a
Philadelphia flourmill in 1794.

9. ADVANTAGES OF INSTRUMENTATION
AND CONTROL
♦ Production & Quality
wise
♦ Material Savings
♦ Cost Savings
♦ Production Inspecting and
Testing
♦ Plant Safety and Comfort
♦ Less man power/automatic

10. INSTRUMENTATION APPLICATIONS
♦ Building automation, HVAC control
♦ Fire protection system
♦ Construction and Design
♦ Food and Beverage
♦ Glass and Ceramics
♦ Mining and metals
♦ Chemical, Petroleum, Refineries
♦ Pharmaceutical and Medical
♦ Pulp and Paper, Textile
♦ Water and wastewater
♦ Power Plant
♦ Semiconductor
♦ Robotics Technology
♦ Aerospace, Automotive and Vehicle

11. STANDARDS REFERENCES
ISA Instruments, Systems and Automation (formerly
Instrument Society of America)
ANSI American National Standards Institute
SAMA Society of Apparatus Makers Association
ASTM American Society for Testing Materials
ISO International Organization of Standards
ASME American Society of Mechanical Engineers
IEEE Institute of Electrical and Electronics Engineers
NEMA National Electrical Manufacturer’s Association
SI International System of Units
NBS National Bureau of Standards
IN INSTRUMENTATION

12. Mathematics
Chemistry &
Chemical
Engineering
Metallurgical &
Manufacturing
Engineering
Electronics &
Communications
Engineering
Mechanical &
Electrical
Engineering
Information
Technology &
Computer
Engineering
Nucleonics
INSTRUMENTATION
AND
CONTROL
Physics
Instrumentation and Control effects and
interaction with Science and Technology

13. INSTRUMENT AND CONTROL LOOP
• a group of instruments together with a process in
order to measure or control a single variable.
=Four elements of Instrument Loop=
1. Process
• pressure, temperature, level, flow, signal
instrument
2. Measuring Element
• Sensor, transmitter, transducers, etc.

14. =Four elements of Instrument Loop=
3. Receiving Element
• Indicators, recorders, controllers, alarms, etc.
4. Final Control Element
• Control valve, dampers, motor drive,
relay, etc.
INSTRUMENT AND CONTROL LOOP

15. INSTRUMENTATION LOOP BLOCK DIAGRAM

16. Process
• A physical or chemical change of matter, or
conversion of energy.
Process Control
• technique of balancing supply and demand over
a period of time at a pre-determined level of
operation called “set point” (SP).

17. • The controller compares the measured variable
(PV)) with the set point and then makes an
adjustment in the final control element based on
the difference between the set point and the
measured variable and this is the error signal (e).
Process Control
PV - SP = e
Measured Variable – Setpoint = Error

18. •Gauges
•Valves
•Transmitters
• Switches
SOME INSTRUMENTS USE IN
PROCESS CONTROL
• Alarms
• Recorders
• Surveillance
• Detection
• Controllers

19. INSTRUMENT PROCESS VARIABLES
1. Pressure
2. Flow
3. Level
4. Temperature
5. Viscosity, Humidity, Specific Gravity, pH,
conductivity, etc.
Variable – A physical quantity or property that can be
measured. Also known as the measurand.

20. A. Pressure
• Is defined as force per unit area.
• It is the force exerted by an object on a certain area.
P = F / A
where,
P = Pressure
F = Force acting on a
surface
A = Unit Area of
Surface
1 inch
1”
100
lbs.
An object weighs
10 pounds is
resting on an area
of one square inch,
it is exerting a
pressure of 100
pounds per square
inch (100 psi)
INSTRUMENT PROCESS VARIABLES

21. Forms of Pressure Measurement
1. Atmospheric Pressure - is the pressure caused
by the weight of the atmosphere.
2. Absolute Pressure - is the total pressure
exerted. It is measured with respect to a reference
called absolute 0 pressure less than this (meaning
a negative absolute pressure.
Absolute Pressure
= Atmospheric Pressure + Gage Pressure
INSTRUMENT PROCESS VARIABLES

22. 3. Gage Pressure – is the pressure with respect to
the atmospheric pressure. It can be higher than
atmospheric pressure, which makes it a positive
value. Or it may be lower than the atmospheric
pressure, which makes it a negative value.
4. Vacuum Pressure – the negative pressure. If we
call it vacuum pressure, we no longer give the value
a negative sign.
5. Differential pressure – the difference between
two pressures.
Forms of Pressure Measurement
INSTRUMENT PROCESS VARIABLES

23. Pressure Scales
INSTRUMENT PROCESS VARIABLES

24. • movement of a liquid, a gas, or a
vapor from one place to another.
B. Flow
• may be defined as the height or
depth of a liquid or solid surface from
a datum or reference point.
C. Level
INSTRUMENT PROCESS VARIABLES

25. The level measurement can be either
continuous or point values.
• Continuous level sensors measure level
within a specified range and are used to know
the exact amount of liquid in a certain place.
• Point level sensors only measures a specific
level, generally this is used to detect high
level alarms or low level alarms.
INSTRUMENT PROCESS VARIABLES
C. Level

26. D. Temperature
• It is a condition of a body, which determines the
transfer of heat to and from other bodies.
• It is the measure of its molecular activity.
Temperature is not a measure of heat.
• It is the ability to transfer heat.
INSTRUMENT PROCESS VARIABLES

28. SETPOINT
• An input variable that sets the desired
value of the controlled variable.
MANIPULATED VARIABLE
• The quantity or condition that is varied as a
function of the actuating error signal in order to
change the value of the directly controlled variable.
CONTROLLED VARIABLE
• The variable that the control system attempts to
keep at the set point value. The set point may be
constant or variable.

29. OPEN LOOP
• A system in which does not use feedback.
CLOSED LOOP
• A system in which the output is fed back and
compared with the input.
SIGNAL
• a variable that carries information about another
variable it represents

30. IMPULSE LINE
• sensing line, tubing or pipe, that connects
the process to the primary measuring
element of the instrument loop and is part
of the process pressure boundary and
containment.
IN-LINE INSTRUMENT/DEVICE
• instrument/device installed in the process piping
system (e.g. control valves, orifice plates,
thermowell, etc.)

31. PROCESS AND INSTRUMENTATION
DIAGRAM ( P & ID )
• This is a drawing that represents the process
with their corresponding instruments.
• A schematic illustration of functional
relationship of piping, instrumentation
and system equipment components. It is
used to operate the process system.

32. LOOP
● A combination of two or more instruments or
control functions arranged so that signals pass
form one to another for the purpose of
measurement and/or control of a process variable.
SYMBOLS
● A representation of an instrument valve or other
process equipment often identified by letters and
numbers

33. INSTRUMENT LOOP DRAWING
• is a drawing that shows all the connections for
the instruments and other devices in a complete
loop, including field junction box terminals,
marshalling panel terminal blocks,down to DCS
panel.

34. INSTALLATION DETAIL
• installation documentation in the form of
standards, specifications, procedures, drawings,
and quality inspection plans.
MATERIAL TAKE-OFF
• an estimate of materials showing its description
or specifications, and its quantity.

35. LOCAL OR FIELD-MOUNTED
• The location of an instrument that is neither on a
panel nor mounted in a control room. Local
instruments are commonly in the vicinity of a
primary element or a final control element.
PANEL / BOARD
• A structure that has a group of instruments
mounted on it, houses the operator-process
interface, and is chosen to have a unique
designation. The panel may consist of one or more
sections, cubicles, consoles, or desks.

36. PANEL-MOUNTED
• A term applied to an instrument that is
mounted on a panel or console and is
accessible for an operator’s normal use.
LOCAL PANEL
• A panel that is not a central or main panel.
Local panels are commonly in the vicinity of
plant subsystems or sub-areas.

37. LINE MOUNTED INSTRUMENT
• an instrument installed directly connected to
the process piping system (e.g. temperature
indicators, temperature elements rotary flow
meter, control valves, orifice plates & flow
switches).
LOCAL MOUNTED INSTRUMENT
• an instrument installed locally on a
wall, column, floor stand, etc. (e.g.
transmitters,switches, indicators)

38. BEHIND THE PANEL
• a term applied to a location that is within an
area that contains (1) the instrument panel, (2)
its associated rack-mounted hardware, or (3) is
enclosed within the panel.
• Behind the panel devices are not accessible for
the operator’s normal use.

39. CALIBRATION
• A comparison of two instruments or measuring
devices, one of which is a standard of known
accuracy traceable to international standard, to
detect, correlate or eliminate by adjustment any
discrepancy in accuracy of the instrument or
measuring device being compared with the
standard.

40. BENCH CALIBRATION
• Usually done in an instrument calibration
van / workshop with a proper hook-up
procedures and complete documentation as
per manufacturers instruction manuals.
ACCURACY
• The degree of conformity of an indicated value to
a recognized, accepted value, or ideal value.
• is the ratio of the error to the full-scale output.

41. AS-LEFT
• the final data after the calibration
made.
AS-FOUND
• the initial reading/indication prior to calibration.
• the reference data for zero adjustment or a span
adjustment .

42. POINTER ADJUSTMENT
• repositioning the pointer relative to the scale is
called “re-zeroing” the gauge.
• shall be done at the minimum scale value.
SPAN ADJUSTMENT
• A potentiometer were to adjust only the span
ratio expressed in percent, minimum & maximum
scale of span.

43. HAIRSPRING ADJUSTMENT
• the hairspring's function is to take up clearance
in the movement and linkage. It should be adjusted
with tweezers to set them perfectly level so that
when wound up approx. 360º., they will not distort.
LINEARITY ADJUSTMENT
• when the motion of the pointer slows down or
speeds up at the end of the range as the pressure
is increased in uniform increments, rotary
movement is rotated either downward or upward.

44. AMBIENT TEMPERATURE
• room temperature, a certain temperature within
enclosed space at which human beings are
accustomed,
RELATIVE HUMIDITY (RH)
• is a ratio, expressed in percent (%
RH), of the amount of atmospheric
moisture present relative to the amount
that would be present if the air is
saturated.

45. SPAN
• the difference between the upper range and
lower range values expressed in the same units
as the range.
OPERATING PRESSURE
• the actual (positive or negative) pressure at
which a device operates under normal
conditions.

46. WET LEG
• a liquid filled sensing line in a differential
pressure level measuring system.
PINION
• the center portion of pressure
gauge where the pointer is attached.

47. STANCHION
• a structure wherein an instrument
such as transmitter is mounted with a
standad height from its base.
PIGTAIL
• A 270º or 360º loop in pipe or tubing to form a
trap for vapor condensate. It is used to prevent
high temperature vapors form reaching the
instrument.

48. ROOT VALVE
• the first valve located in a sample line after it taps
off the process. It is typically located in close
proximity to the sample tap.
THERMOWELL
• A pressure tight receptacle connected to a
temperature sensing element and provided with
external threads or other means for pressure tight
attachment to a vessel.

49. MILLIAMP (mA)
• one thousandth of an ampere.
MILLIVOLT (mV)
• one thousandth of a volt.
VENT valve
• use for venting excess pressure or gas trap in
the process line.
DRAIN valve
• use for draining excess liquid or steam
accumulating in the process line or seal pots.

50. SEAL POT
• enlarge pipe sections in measurement
impulse line to provide:
a. A high area to volume displacement ratio to
minimize error from hydrostatic head
difference when using large volume
displacement measuring elements
b. To prevent loss of seal fluid by displacement
into the process.

51. LOCK OUT & TAG OUT (LOTO)
LOCK OUT
• to place a suitable padlock on an energy-
isolating device of a machine or on
equipment to prevent un-authorised or
accidental operation of the machine or
equipment where work is in-progress.
• Energy isolating devices includes circuit
breakers, switches, valves, blocks, etc.

52. TAG OUT
• an information or identification tag which
is securely fastened to an energy-isolating
device under lock-out, to indicate the
identity of the person and nature of work
conducted on the said equipment or
device.
LOCK OUT & TAG OUT (LOTO)