types of nucleonic gauges

R. H. Chilkulwar

Radiological Physics & Advisory DivisionBHABHA ATOMIC RESEARCH CENTRE

Measurements in real timeContact less (non-destructive)No maintenanceNo effect of environmental factorsData obtained usually over large

material quantities

Alpha, α 210Po, 239Pu, 241Am

Beta, β 3H, 85Kr, 63Ni, 90Sr, 147Pm, 204Tl

Gamma, γ 60Co, 137Cs, 170Tm, 241Am

X-rays 55Fe, 109Cd, 57Co

Neutron, η 206Ra-Be, 210Po-Be, 241Am-Be

Transmission

Backscatter

Activation

Physical parameters

LevelThicknessDensityQuantity

• Chemical parameters

• Moisture• Metal content etc.

• Applications: paper manufacturing, metal sheet, PVC foil rolling, rubber foil, plate glass, textile fibre slab, artificial leather manufacturing.

Coating thickness measurement: XRF, scattering, activation

XRF technique is used for Coating thickness measurements up-to 20 microns of galvanized, paints etc.

Ore analysis

Measurement is based upon the radiation absorption dependence on the product ρ.l

I = Io e-µm ρ l

ρ – density l – material thickness in m or cm µm – mass absorption coefficient

Applications : soil density, soil compactness testing, Tobacco trunk density in Cigarette manufacturing etc.

Isotopic belt weigher in coal mines, coal-fired power plants, floating suction dredgers, hydraulic fly ash removal at power plants, cement manufacturing heat exchangers.

For quality measurement, the processing substances should not have moisture content above the well-defined limits. To monitor and control it online, neutron sources are used.

Scattering and moderation – inelastic scattering with low z material hydrogen.

Disturbance and noise in measurement due to presence of highly neutron absorbers B, Cd etc and presence of low z materials Cl, O, S. This can be rectified using density measurement with gamma source

Application: concrete fabrication, ore dressing, blending of ceramic materials, glass production, foundry sand conditioning, building materials

Includes various physical and physicochemical measurements and techniques applied in drill holes for determination of different properties of the penetrated rocks, conditions of well etc.

It is carried out with “Sonde” containing transmitter-receiver pairs.

Types:Borehole probesSurface monitor

Multi-energy gamma energy absorption (MEGRA) technique for Multiphase flow rate measurements

Portable Nucleonic Gauges

Computed Tomography (CT)

Radiometric Analyzer

(Nat. Radioactivity gauge for

online analysis of U, Th & K)

Number of Institutions 1010Level gauges 3559Density and moisture gauges

1062

Thickness gauges 536Well logging tools 486Betascopes 156Others 714