▼measurement index
quantification (g / m2), thickness (μ m).
▼application area
paper, film, non-woven cloth, cloth, metal sheet, and other surface width materials.
▼mainly constitutes
isotope ray sensor consists of the transmitter head and the receiver head.
the launch head mainly includes: emission head box, isotope radioactive source (kr85 or pm147), lead sealed container, micro guide rail, single-acting cylinder, magnetic proximity switch, controlled measurement window, etc.
the receiving head mainly includes: receiving head box, ionization chamber, dc high-voltage power supply, signal transport and discharge circuit board, signal processing circuit board, communication circuit board, measuring window film, etc.
▼measuring principle
the absorption attenuation of the material through the e-ray roughly follows the beer's law; the sensor transmitting head controls the measuring window to emit the e-ray through the measured medium into the receiving head, and the ionization chamber and electronic circuit in the receiving probe receives the rays that weaken through the absorption of the measured substance and transforms the electrical signals proportional to the intensity of the receiving ray. by establishing the mathematical model of the measured medium (surface density) and the measured electrical signal, the nonlinear function constant is determined by the big data fitting the relationship between the measured medium and the signal.
in the applied measurement, the density of measured medium is calculated by measured signal function interpolation.
figure 1: plot of radioactive source signal attenuation intensity and measured surface density
beer's law of ray absorption through matter: i=io * exp (- μ * bw)
i= has the subject object sensor signal, io= the space-gap sensor signal; bw= the surface density, μ = the mass absorption coefficient.
▼technical characteristics
◆ the often closed cylinder directly push the shutter, and the equipment fault automatically closed the ray source.
◆ the lead tank sealed ray source is tightly screened, and the environmental radiation index is reached outside the range of 30cm around.
◆ 8-15mm measures the gap with the shortest ray air path and the lowest environmental interference.
◆ the β ionization chamber type matches the radioactive energy spectrum with high sensitivity and wide linearity.
◆ precision microelectronics circuit, high stability, high signal to noise ratio, large dynamic range.
◆ the receiving gain gear can be controlled to accommodate the attenuation degree of the radioactive source and maintain good signal quality.
◆ receives constant temperature heating in the chamber and prevents condensation in the measurement window to ensure the stability of the measured environmental parameters.
◆ this is not affected by the material composition, color, density, or thickness, and directly reacts with the measured physical indicators.
◆ online transmission type nondestructive testing.