PT series ultrasonic thickness meter is  Beijing PengXiang  technology co., LTD launched a new generation of ultrasonic thickness meter.PT900 type intelligent ultrasonic thickness gauge using ultrasonic pulse echo to measure thickness of various kinds of materials.Can be directly read out the thickness of the material and the velocity of the test material value, has been widely used in various fields of applications.With a simple to use, complete function, small size, high reliability, etc.
PT900 ultrasonic thickness meter
Super light thin body, easy one-handed operation
Two calibration function, makes the measurement more accurate
Unique blue background light, clearly visible in all kinds of environment
Low power consumption, two batteries can be used more than 200 hours
Suitable for measuring all guide material, such as steel, iron, plastic, ceramic, organic glass, etc
The basic principle of PT900 ultrasonic thickness meter
Ultrasonic thickness meter is based on the principle of the ultrasonic pulse reflection for thickness measurement, when the launch of the ultrasonic pulse probe through the material object to be tested interface, the pulse is reflected back to the probe, through the accurate measurement of ultrasonic wave propagation in the material time to determine the thickness of the material being tested.Those that make the ultrasonic wave at a constant speed in its internal communication of various materials on the principle of the measurement.According to the principle of the design of the thickness gauge can accurately measure about all kinds of plates and all kinds of machining parts, can be all kinds of pipeline and pressure vessel in the production equipment to monitor, monitor them in the process of using the degree of corrosion after thinning.Can be widely used in petroleum, chemical industry, metallurgy, shipbuilding, aviation, aerospace and other fields.
PT900 ultrasonic thickness gauge using techniques and factors affecting the accuracy of measurement
1, the general measurement methods:
(1) in a place with a probe for two thickness, the two split face to each other in measuring probe 90 °, measured the thickness of the workpiece is a smaller value.
(2) 30 mm multipoint measurement method: when the measured value is not stable, with a measuring point as the center, in many times within the circle of about 30 mm in diameter measurement, taking the minimum value to be measured the thickness of work piece.2, accurate measurement method: increase the number of measurement around the specified measurement point, expressed in isopach thickness changes.
3, continuous measurement method: along the designated route continuous measurement with single point measuring method, interval is not more than 5 mm.
4, grid method: in the designated area in the grid, the thickness at the record.This method in the high voltage equipment, stainless steel liner is widely used in corrosion monitoring.
5 and the influencing factors of ultrasonic thickness meter value indicated:
Large (1) the surface roughness of workpiece and the probe and the interface coupling effect is poor, low echo, and even can't receive the echo signal.For surface rust, and coupling effect is poor equipment and pipelines in service through sand, grinding, cutting method for surface treatment, such as lower roughness, oxide layer and paint can be removed at the same time, with metallic luster, make the probe and were seized by the coupling agent can achieve very good coupling effect.
(2) the workpiece curvature radius is too small, especially the small tube thickness, for common probe surface is flat, contact with the surface of point contact and line contact, low sound intensity transmissivity (coupling).Can choose special probe (6 mm), small diameter can more accurate measurements of pipeline surface materials, etc.
(3) the detection of surface and bottom surface is not parallel, sound waves encountered bottom scattering, the probe can't accept what wave signal.
(4) the austenitic steel castings, due to uneven or coarse grains, in which ultrasonic through severe scattering attenuation, scattering of ultrasonic wave propagation along the path of complex, has the potential to echo annihilation, cause is not shown.Can choose the coarse grain special probe of low frequency (2.5 MHz).
(5) probe interface has some wear and tear.Commonly used thickness probe surface for the acrylic resin, long-term use can make the surface roughness increases, resulting in a decline in sensitivity, resulting in the display is not correct.Can choose 500 # sandpaper, make it smooth and ensure parallelism.If it is still unstable, consider replacement probe.
Analyte (6) there is a lot of corrosion pits on the back.Analyte due to the other side has a rusty spot, corrosion pits, cause the acoustic attenuation, lead to reading no rules change, in extreme cases even without reading.
(7) (such as pipe) object to be tested with sediment, sediment and artifacts when acoustic impedance difference is not big, thickness gauge display value of wall thickness and thickness of sediment.
(8) when the intrinsic defects in the material (such as inclusions, sandwich, etc.), the display value about 70% of the nominal thickness, such as defect detection by ultrasonic flaw detector further at this time.
(9) the influence of the temperature.Average velocity of solid materials decreases with the temperature, and there are test data show that hot materials increase 100 ° C, a 1% drop in the speed of sound.For high temperature equipment in service often encounter this kind of situation.Should choose special high temperature probe (300-600 ° C), do not use the ordinary probe.
(10) cascading material, composite (heterogeneous).To measure without the coupling of the laminated material is not possible, due to the ultrasonic cannot penetrate without coupling space, and are not uniform in the composite (heterogeneous) transmission.For equipment made of multi-layer material bandage (like urea HP equipment), should pay special attention to when thickness, thickness gauge says only the value of the material thickness is in contact with the probe.
The influence of coupling agent (12).Coupling agent was used to eliminate the probe and the air between the object to be tested, make the ultrasonic wave detection can effectively through the workpiece to achieve.If choose types or improper use, will cause the error or coupling symbol flashing, you can't measure.Because, according to the types of usage for choosing appropriate when materials used in the smooth surface, the coupling agent can use low viscosity;When used at the top of the vertical surface and rough surface, surface, high viscosity of the coupling agents should be used.High temperature artifacts should choose high temperature coupling agent.Secondly, coupling agent should be used in moderation, evenly daub, general coupling agent should be coated on the surface of the material being tested, but when the temperature is higher, the coupling agent should be coated on the probe.
Select error (13) sound.Measurement of workpiece, the speed of sound or according to the standard block according to the material types preset counter measure the speed of sound.After correction instrument with a material (commonly used for block, steel) and to measure when another material, will produce the wrong results.Requirements must correctly identify materials before measurement, appropriate velocity of sound.
(14) the effects of stress.Equipment in service, most of the pipeline stress exists, the stress condition of solid materials has certain influence to the velocity of sound, when stress direction is consistent with the direction of propagation, if stress is compressive stress, the stress increase the elasticity of artifacts, velocity of sound speed up;On the other hand, if stress is tensile stress, slowed the speed of sound.When stress with the direction of wave propagation is differ to, fluctuations in the process of particle vibration trajectory, the influence of the stress wave propagation direction deviation.According to the data show that average stress increases, the speed of sound increases slowly.
(15) metal surface oxide or the influence of paint coating.The density of the metal surface oxide or paint coating, though close integration with the base material, no obvious interface, but the speed of sound propagation velocity in two kinds of material is different, resulting in the error, and with the cover thickness is different, the error size is also different.

Four display: LCD digital display
Measurement: the ultrasonic pulse echo
Measurement frequency: 5 MHz
Measuring range: 1.0 200.0 mm (steel)
Accuracy: + 0.5% (H + 0.1) mm
Sound velocity range: 1000-9999 m/s
Display period: 0.5 seconds
According to maintain time: about three minutes
Coupling indicates: in at the upper left of the LCD display "please"
According to its battery runs out: in the left side LCD display "-"
Dimension: 119 (L) x 64 (W) x 22 mm (H)
The host weight: 125 g
The calibration block: 3.0 mm calibration block
The probe contact area: Φ 10 mm
Power supply: two 5 alkaline batteries
Boot time: about 1 second
Battery life: 200 hours
Using the environment temperature: - 20 ℃ to + 50 ℃
The probe weight: 50 g
Probe models: PTS5 (standard)
PTH5 (high temperature type, optional)