juhi-salimaki-fieldbus_calibration[1].pdf

Fieldbus transmitter must also be calibratedFieldbus transmitter must also be calibrated

Mr. Juha Salimaki

Area Sales Manager, Country Manager - India Beamex Oy, Finland

1. What is calibration

2. Why calibrate

3. The operation of fieldbus transmitters

4. Fieldbus transmitters must also be calibrated

5. The principles of calibrating fieldbus transmitters

6. Conventional way of calibrating fieldbus transmitters

7. New solution - Calibrating fieldbus transmitters with a Beamex MC5

ContentsContents

What is calibrationWhat is calibration

What time is it? What time is it exactly and how do you know it?

Calibration can be briefly described as an activity where the instrument being tested is compared to a known reference value.

The keywords here are known reference, which means that the known reference used in the comparison should be traceable to some standard.

Terminology differs between conventional and digital instrument calibration.

Why calibrateWhy calibrate

The primary reason for calibrating is that even the best instruments drift and lose their ability to give accurate measurements.

The drift makes calibration necessary.

Environment conditions, elapsed time and type of application can all affect the stability of an instrument.

Even instruments of the same manufacturer, type and range can show varying performance. One unit can be found to have good stability, while another performs differently.

Other reasons for calibrationOther reasons for calibration

To maintain the credibility of measurements.

To maintain the quality of process instruments at a good-as-new level.

Safety and environmental regulations.

ISO9000, other quality systems and regulations (e.g. FDA).

ISO9000 and ISO14000 can assist in guiding regular, systematic calibrations, which produces uniform quality and minimizes the negative impacts on the environment.

The operation of fieldbus transmittersThe operation of fieldbus transmitters

Conventional transmitters

Analog one-way signal

Only one variable

A pair of cable to each instrument

Conversion of mA signal to digital for I/O subsystems

Control System

PT-101

PT-102

CV-101

I/O SUBSYSTEM

4-20 mA

4-20 mA

4-20 mA

The operation of fieldbus transmittersThe operation of fieldbus transmitters

Fieldbus transmitters

Digital two-way signal

Huge amount of information is transferred

Several instrument in one bus cable(multi-drop)

No conventional I/O systems needed

Open standard Instruments from any manufacturer can be in the same fieldbus

Control System

SEGMENT CONTROLLER

HOST-LEVEL NETWORK(Profibus DP, Foundation HSE, etc)

PT-101

CV-101

FT-101

F

I

E

L

D

-

L

E

V

E

L

N

E

T

W

O

R

K

(

P

r

o

f

i

b

u

s

P

A

,

F

o

u

n

d

a

t

i

o

n

F

i

e

l

d

b

u

s

H

1

)

Fieldbus transmitters must also be calibratedFieldbus transmitters must also be calibrated

The main difference between a fieldbus transmitter and conventional transmitters is that the output signal is a fully digital fieldbus signal.

Changing the output signal does not change the need for periodic calibration.

Although modern fieldbus transmitters have been improved compared to older transmitter models and some manufacturers gives assurance of drift-free instruments, it does not eliminate the need for calibration.

Calibrator is needed to measure (generate) input + a way to read the digital output

Process Digital Output

Fieldbus transmitter

Pressure, Temperature,Voltage, Current, Pulse,Resistance, etc

The principles of calibrating The principles of calibrating fieldbus transmittersfieldbus transmitters

In brief:

Generate accurate process input

Read FF output

Document results

Trim (adjust) if required

Calibration CANNOT be made remotely e.g. from the control system, etc.

Process Digital Output

Fieldbus transmitter

Pressure, Temperature,Voltage, Current, Pulse,Resistance, etc

Conventional way of calibrating Conventional way of calibrating fieldbus transmittersfieldbus transmitters

Minimum two persons often required

Various measuring instruments needed

Manual documentation of calibration

Doesnt work for stand-alone transmittersFieldbus Process

Automation and Configuration System

CONTROL ROOMFIELD

New SolutionNew Solution

In year 2006 Beamex introduced its revolutionary and awarded Worlds First Fieldbus Calibrator. Till to date no other calibrator manufacturer has been able to introduce anything similar to the MC5 Fieldbus Calibrator

It is a combination of multifunction process calibrator and a fieldbus configurator, which can be used with both industrial standards Foundation Fieldbus H1 and Profibus PA

Calibrating fieldbus transmitters Calibrating fieldbus transmitters with the Beamex MC5 Fieldbus Calibratorwith the Beamex MC5 Fieldbus Calibrator

1. Make connections(live segment or stand-alone)

- View/edit instrument configurations

- Verify the instruments during commissioning

2. Calibrate and document automatically

- Simulate or generate the input and read the digital output of the Fieldbus instrument

3. Trim (adjust) if required and perform As Left calibration automatically or manually

4. Upload calibration results to calibration software and print the calibration certificate

Thank You Thank You KIITOS!KIITOS!