nuclear measurement download it

Radiometric Measurement

1

Nuclear Level Measurement

Introduction

Radiation / Safety

Basics

Introduction

Radiation / Safety

Basics

Installation

Introduction

Radiation / Safety

Basics

Introduction

Basics

Calibration

Applications


2

Why Radiometric Measurement

Hightemperatures

ToxicityHigh

pressures

Abrasion Installations

Viscosity Design

Used when other methods failed,

because of extreme process conditions ...


3

Limitation of measuring principles

0 4 40Pressure

[bar]

Radiometric

Level RadarMicropilot

Ultrasonic

Guided Level RadarLevelflex

160

150

Temp.[°C]

400

350

420

Differentialpressure

For continuous level measurement


4

Source +Source container

Compact-transmitter(Detector)

Radiometric measurement

Absorptionby the medium


5


• non contact measurement • non invasive measurement,

the measuring system is fitted externally and measures through the container wall

• it offers process safety, reliability and availability of the facilities

• for Continuous level measurement

Limit detection

Density measurement

Interface measurement


6

Radiation / SafetyIntroduction

Radiation / Safety

Basics

Installation

Calibration

Introduction

Radiation / Safety

Introduction

Radiation / Safety

Introduction

Applications


7

Radiation

Visible = 400 - 750 nm

10-5 10-2 104 1063 102

Gamma X-Ray

Th

erm

al IR

Mic

row

ave

Refl

ecte

d I

R

UV Radio

Vis

ible

(µm)

400 500 600700

Spectrum of Electromagnetic wavesGamma radiation is an electromagnetic wave

Electromagnetic waves are oscillations of electric and magnetic fields, which spread out with speed of light in the spaceand transport energy.

Gamma Gamma radiationradiation

• short wave length = 10-5 - 10-7 µm• very high frequency• ionising radiation ( < 100 nm)• high-energy photons (higher energy than light)


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Radiation comparison

Sender: Energy

Receiver: Power

Intensity of light[watt]

Activity[mCi] / [Bq]

illumination[lux]

Dose rate[Sv/h]

Gamma Visible

r


9

Radiation come into existence

Number of emitted radiation per time:

Activity = 1 decay/s = 1 Becquerel (Bq)

1 Curie (Ci) = 37 GBq

3 types of radiation

Alpha particle radiation

Beta particle radiation

GammaGamma electromagnetic wave electromagnetic wave

Inside sourcematerials• Cs 137• Co 60

A spontaneous decay of an atom is a radioactive decay, which emits radiation.

Source material

Source

Atom

Cs137 and Co60 no alpha decay


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Radiation penetrate materials

1,5 kg/dm³

2,7 kg/dm³

Mica

Alu

Steel

Lead

7,89 kg/dm³

11,3 kg/dm³

=

=

=

=

Density values

Mica

Alu

Steel

Lead

Alu-FoilMica

Steel

Lead

Penetrate

each material

Attenuation

Absorption


11

Radiation - Unit for attenuation

100 %

1 x HVL 50 %

2 x HVL 25 %

Thickness of a layer, which reduce the dose rate to the half.

1 HVL for Cs

137

14,5 mm steel

9 mm lead

90 mm water

40 mm concrete

1 HVL for Co

60

20 mm steel

12 mm lead

120 mm water

55 mm concrete

beam path

Half value layer (HVL)

Dose rate

5 HVL ~ total absorption of the radiation


12

Radiation - Distance principle

Source

Distance r (m)

12

43

Dose rate decreases with the square of the distance

Distance principle for electromagnetic waves

100%

25%

2

1

r:law Distance 2

1

r:law Distance

6,25%


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Radiation - Basic rules for radiation protection

distance

timeshielding

Dose rate [Sv/h] is depending on


14

BasicsIntroduction

Radiation / Safety

Basics

Calibration

Introduction

Radiation / Safety

Basics

Introduction

Radiation / Safety

Basics

Introduction

Radiation / Safety

Basics

Installation

Applications

• Level Measurement

• Measuring principle

• Radiation beam

• Measuring tasks

• Terms


15

Level measurement

Master

Slave

Slave

End-Slave

4...20 mA

Master Slave4...20 mA

• Double sensitivity or redundant measuring system

• Large measuring range (with cascade)

Level Measurement - Std principle

• Nuclear type devices work on the principle that process material absorbs (attenuates) radiation.

• On the outside of one wall of the vessel, an installed nuclear source emits radiation. A nuclear detector is installed on the outside of the opposite vessel wall.

• The nuclear source and detector are usually built in a “strip” type of form.

• The type of radiation is usually gamma rays (X rays). As the radiation beams from source to detector, the process material absorbs some of the gamma rays.

• The amount of absorption is based upon the process material’s density and the current process material volume within the vessel.

• As the liquid level rises, the liquid absorbs more of the radiation than the gas or air above the liquid. As the liquid level rises,

• the radiation detected decreases. The increase in level is determined from the decrease in detected radiation.

Source +Source container

Compact-Transmitter(Detector)


17

Density measurement

Features of sensor models Highest stability ± 0.1%

with NaI (sodium iodide)

crystal

50 x 50 mm

Well-priced solution with

PVT- plastic

(stability ± 1%)

40 x 200mm/400 mm

Selection of output signal Density (0.5 ... 3.0 g/cm3) Concentration Solid contents in liquids

(% Weight, % Volume,

weight/volume) Density, temperature

compensated

with PT100

FMG60

D


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Radiation beam

Compact-transmitter(Detector)

6°

5°20°

40°Source +Source container


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Physical effect

Photoelectric absorption

The total energy of the radiation transfers to

the electron.

The radiation is absorbed completely in the

medium.

e-

Atom

E = h · f

Absorptionby the medium

e-

e-


20

Measurement tasks

Limit detection

Level

Density / Mass flow

Interface

100%

0%

35%

0 1000

Level

Pulse rate in c/s

5°

20°/

40°


21

Terms

Distance A [m]

Absorptionby the medium K

FiFsFaP

K

FiFsFaP

• Activity (P)

• distance from the source

(Fa = A2 )

• thickness and density of

the

material in the beam path

(Fs = )

• Dose rate (Fi)

• source energy (in factor

K)

deqke

Calculation of the activity:

Source:ActivityP [Bq] or [mCi]

Detector:Dose rate Fi [Sv/h]


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Product range

Source Source container Compact transmitter

Integrated detector + transmitter

137CsActivity:1 / 2 / 3 / 510 / 20 / 30 / 50 / 100 / 200250 / 300500 mCi

60CoActivity:1 / 2 / 510 / 20 / 50 / 100 / 200 mCi

QG 020 Standard- / Chemical- / Sweden(Euro)-Design

QG 100 Standard- / Chemical- / Sweden(Euro)-Design

QG 2000

With nipple(standard design)

or thread(chemical design)

Gammapilot-M FMG60

Standard or water coolingLength: 200 / 400 / 800 / 1200 / 1600 / 2000 mm

Multifunctional

Diff

ere

nt

length

optionalField housing FHX40with display VU331


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Source container

Lead insteel housing

FlangeOutput channel

Pad-lock

OFF

• Lead for absorption and

• spherical design gives best possible shielding

• Radiation exit angles5° for limit detection20° or 40° for continuous level measurement

• Rotating source insert source holder for On/Off switching

• Pad-locktheft protection and fixing at an defined On/Off position

• For chemical designsource holder with O-ring, prevents the entrance of dust or gas


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FMG60 - Compact transmitter

Multifunctional compact

transmitter

Integrated detector + transmitter

Gammapilot-M FMG60


28

FMG60 - Modular system

CrystalCrystalPlasticPlastic

Flexibility on site due to modular concept

PhotomultiplierPhotomultiplierPhotomultiplierPhotomultiplier

ElectronicElectronicElectronicElectronic

ConnectionConnectionhousinghousing

ConnectionConnectionhousinghousing

ScintillatorScintillator(Sensor)(Sensor)

ScintillatorScintillator(Sensor)(Sensor)

FMG60 - Assembly

Power supplyPeripherycommunication

CPU

Sensor electronic

HV electronic

Photo multiplier tubescintillator

Housing pipe

Volume reducer

Housing head

Ex i connector board

Magnetic shield


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FMG60 - Functional principle

Scintillator material:NaI-Crystal 50x50

PVT Plastic 40 x L 200 ...

2000mmAmbient temperature -40°C ...

+50°C

with water cooling +40°C ...

120°C

Functional principle: radiation entering the

scintillator

attenuation generate a tiny

flash of light

photocathode convert in

electrons

photomultiplier convert

into voltage pulse

signal processing count the

pulses

Functional principle: radiation entering the

scintillator

attenuation generate a tiny

flash of light

photocathode convert in

electrons

photomultiplier convert

into voltage pulse

signal processing count the

pulses

Scintillator(Sensor)

Photo-multiplier

Electronic

Rod housing1.4435 / SS316

Connectionhousing

Gammaradiation


31

FMG60 - Connection housing

Compartment for Ex iOutput and Periphery Temperatu

rePT100

Service/Display

FF DIP-switch

Cascade: Master/Slave

Output:4...20 mA HART orProfibus PA or FF

Power supply:90 ... 253 V AC18 ... 32 V DC

Compartment for Ex e or Ex dPower and Output

OR

Stainless steel SS316

Installation conditions for level measurement

Conditions• For level measurements the Gammapilot M is mounted vertically; if possible

the detector head should point downwards.

• The exit angle of the source container must be exactly aligned to the measuring range of the Gammapilot M. Observe the measuring range marks of the Gammapilot M.

• In cascading mode no gap should occur between the measuring ranges of the different Gammapilot M.

• The source container and the Gammapilot M must be mounted as close to the vessel as possible. Any access to the beam must be blocked so that no persons or part of their body (hand, arm, head) may come into the area of the beam.

• In order to enlarge the lifetime, the Gammapilot M should be protected against direct sun. If necessary, a protective cover should be applied.

• The mounting device FHG60 (see chapter "Accessories)or an equivalent mounting device should be used for fastening the Gammapilot M.The mounting device must be installed in a way such that it can withstand the weight of the Gammapilot M1 under all operating conditions (e.g. vibrations).

Installation conditions for limit detection Conditions

• For level limit detection, the Gammapilot M should be mounted horizontally at the height of thedesired level limit.

• The exit angle of the source container must be exactly aligned to the measuring range of the Gammapilot M. Observe the measuring range marks of the Gammapilot M.

• The source container and the Gammapilot M must be mounted as close to the vessel as possible.Any access to the beam must be blocked so that no persons or part of their body (hand, arm, head) may come into the area of the beam.

• In order to enlarge the lifetime, the Gammapilot M should be protected against direct sun. If necessary, a protective cover should be applied.

• The mounting device FHG60 (see chapter "Accessories)or an equivalent mounting device should be used for fastening the Gammapilot M.The mounting device must be installed in a way such that it can withstand the weight of the Gammapilot M1 under all operating conditions (e.g. vibrations).

Installation conditions for density and concentration measurement

Conditions

• If possible, density and concentration should be measured at vertical pipes with a feed direction from bottom to top.

• If only horizontal pipes are accessible, the path of the ray should also be arranged horizontally to reduce the influence of air bubbles and sediments.

• The Endress+Hauser clamping device (see chapter "Accessories") or an equivalent clamping device should be used for fastening the radiation source container and the Gammapilot M to the measuring tube.The clamping device must be installed in a way such that it can withstand the weight of the radiation source container1 and the Gammapilot M2 under all operating conditions.

Wiring Terminal compartments

The Gamma pilot M has got two terminal compartments:

• terminal compartment A, for– Power supply– Signal output (depending on the instrument version)

• terminal compartment B, for– Signal output (depending on the instrument version)– PT-100 input (4-wire)– Pulse input for cascading mode– Pulse output for cascading mode– Display and operating module FHX40 (or VU331)

Note:• Depending on the instrument version, the signal output is located in

the terminal compartment A or B.


39

FMG60 - Terminal compartments

Ex d

Ex ia

Ex d

Power supply

4…20 mA / HART

Ex e

Wiring in cascading mode

Post-connection check

After wiring the device, carry out the following checks:

• Is the protective earth connected?• Is the Potential Equalisation Line (PEL) connected?• Are the terminals correctly assigned?• Are the cable glands and blind plugs tight?• Are the fieldbus plug connectors and the FHX40 plug fixed securely?• Are the lids screwed tightly onto the terminal compartments?• For Dust-Ex intrusments: Is the protective sleeve for the FHX40

connector correctly attached?• Is the lid of the terminal compartment A secured by the cover clamp?

Warning!The Gammapilot M may only be operated, if the lid of the terminal

compartment is tightly closed.

Calibration for level measurement and limit

detectionBasic principles

The calibration points required for the measurement are entered in the "calibration" (*1) function group. Each calibration point consists of a level and the associated pulse rate.

nuclear measurement download it

Technology

radiation visible

type of radiation

radiation unit

radiation beams

invasive measurement

radiation basic rules

radiation comparison

process safety