Emerald Group Publishing Limited
Copyright © 2000, MCB UP Limited
Range of ultrasonic thickness gauges
Keywords Elcometer, Gauges, Ultrasonic
Elcometer Instruments Ltd inform us that they have launched a new range of ultrasonic thickness gauges to supplement their existing catalogue of products.
The Elcometer 205 (Plate 5), 206 and 206DL digital ultrasonic thickness gauges all claim a wide selection of probe options, so that the transducer can be matched to the form of the component to be measured. Housed in a robust, extruded aluminium case with a sealed membrane keypad for site work, all three versions have a maximum measurement range of 0.63-500mm (0.025-19.999") depending on the choice of transducer.
Plate 5 The Elcometer 205, one of the new range of digital ultrasonic thickness gauges
According to Elcometer with a resolution of 0.01mm (0.001") and a measurement accuracy of ±0.01mm (0.001") depending on the material to be measured and the operating conditions, the 205, 206 and 206DL offer the capability to measure a range of materials when only one side of the sample is available. For example: pipelines, ship hulls, storage tanks, bottle and container walls can all be measured to assess internal erosion or corrosion damage in service.
Three user calibration adjustment methods can be operated. One-point calibration for measurements over a large thickness range, two-point calibration to allow greater accuracy over a small range of thickness, and calibration to a known velocity (without using separately measured samples) to allow accurate measurement of a material whose velocity of sound is known. All three models have the high speed scan mode, which identifies the minimum thickness while moving the transducer over a large area. The lowest reading is stored and displayed when the scan is finished.
All versions have a back light fitted for use in low ambient light conditions. The 206 and 206DL have data output capability for operating with printer or computer, will display the positive or negative difference between a pre-set nominal thickness (target) value and the actual reading and have an audible and visual alarm when the reading falls below this value.
The 206DL also has a memory of up to 1,000 readings and will operate with the Elcometer data transfer system (EDTS), to upload the data via a cable to a PC; this is supplied free of charge.
These small, 63.5 x 120.6 x 31.75mm (2.2 x 4.75 x 1.25"), lightweight, 295g (10oz), battery powered gauges carry a five-year warranty on all non-consumable parts and provide another opportunity for Elcometer customers to choose the gauge that is most suitable for their application.
Also new from Elcometer are test kits for the detection and measurement of soluble salts on steel surfaces. Known as the Elcometer 134 CHLOR*TEST salt detection kit and aimed particularly at marine painting applications, this kit is thought to offer a quick and simple method for the assessment of surfaces for chlorides prior to coating.
The presence of chloride ions as contamination on the surface of a steel structure has the potential to cause premature coating failure due to corrosion at the surface of the steel. Cleaning the steel surface will only be effective if, in addition to removing rust, these soluble salts are also removed. A simple field test to determine the level of such salts, accurately, will help to ensure a coating that will achieve its full operating life.
The Elcometer 134 is said to be convenient to use with its four-step process:
Pour CHLOR*EXTRACT solution into the latex tube.
Peel the protective backing off the flange of the tube, pinch the tube to retain the CHLOR*EXTRACT and stick the flange to the surface to be tested.
Work the solution against the surface to extract the salts and peel the flange off.
Insert the glass titration tube into the solution in the tube and read the result.
This process takes about five minutes and a simple colour change in the tube registers the level of chloride ions in both parts per million (ppm) or micrograms per centimetre squared (µg/cm2)
The test reportedly has been shown to be very accurate as the CHLOR*EXTRACT will remove at least 90 per cent of the chloride ions present on the surface. This extraction efficiency is measured by comparison to the salts removed by boiling water.
Kits are supplied with sufficient materials to complete five tests and the carton serves as both storage and convenient stand for the tube during the titration tube test.