Surface quality tests

Surface quality tests 23.11.13.1 Barcol hardness test... 

One of the most commonly used measures of durability, i.e. the loss of sodium from the glass, is important to the pharmaceutical and chemical industries, but other changes such as loss of surface quality, are of equal importance for optical and window glasses. The properties of a wide range of technical glasses are well catalogued but the data are often inadequate when considering a particular application and where possible nonstandard whole article tests are advisable. 

Quality tests are usually performed using bench-top, low filed NMR spectrometers. Volume-average properties are determined with this equipment. Surface layer of samples can be analysed using recently developed NMR-MOUSE (mobile universal surface explorer) [26, 188]. The NMR-MOUSE is a relatively small NMR device suited for the investigation of surface-near volume elements. Lateral surface heterogeneity of elastomeric materials can be scanned with this device. Possible applications of the NMR-MOUSE for the characterisation of rubbery materials were demonstrated [26,189-191]. 

With thermal surface impedance testing, heat is injected into the test objects surface from a hot gas pulse. The resulting surface temperature transient is analyzed to determine the bond quality in nearly real time. The surface temperature transients are sensed using an innovative noncontacting, emissivity-independent infrared sensor.27 This method is not adversely affected by surface blemishes or roughness. 

Indicator papers and test papers are strips of paper of suitable dimension and grade (usually Swedish O filter paper or other makes of like surface, quality, and ash) impregnated with a sufficiently stable indicator solution or reagent. 

All specimen are fully wetted (Fig. 5) by the corrosive test fluid (exception R = -1 probes which were only sprayed). The surface quality of the specimen - honed resp. polished - is well comparable to the finish of real pump components. 

It should be kept in mind that any change in surface area, surface chemistry, or microporosity will result in a change in the energy of immersion. Because immersion calorimetry is quantitative and sensitive, and because the technique is not too difficult to apply in its simplest form, it can be used for quality testing. The preliminary outgassing requires the same care as for a BET measurement, but, from an operational standpoint, energy of immersion measurements are probably less demanding than gas adsorption measurements. 

FIGLfRE 7.22 Representative surface quality image of Cu blanket test wafer polished with a slurry consisting of organic abrasive particles. Surface roughness RMS value of... 

In these numerical simulations, the independent variables are (i) wall superheat, (ii) liquid subcooling, (iii) system pressure, (iv) thermophysical properties of test fluid, (v) contact angle, (vi) gravity level, (vii) thermophysical properties of the solid and surface quality (conjugate problem), and (viii) heater geometry. 

Dimensional accuracy and surface quality strength testing by canister manufacturer Dimensional accuracy and surface quality of individual components from dismantled valves... 

Strength tests are made on silicon nitride balls with a large (-31.8 mm) and a small ( 4.8 mm) diameter. It is shown that the surface quality of the balls has a significant influence on their strength. 

The notched ball test is well situated to determine the surface quality of ceramic balls, as they are used in modem ceramic ball bearings. 

However, it is not just transparency and matting efficiency that are important for the appearance and the surface quality of furniture coatings, the chemical resistance must also not be disregarded. Household chemicals were tested in accordance with DIN 68861 Part 1 B. Here too, ACEMATT HK 460 produced some very good results in comparison to other non-coated matting agents (Table 4). For comparison reasons the surface treated ACEMATT OK 520 was included. 

Gel time is also used as a quality-control tool for formulated adhesives. During the cure of an adhesive, its surface is tested every 15 seconds with a clean probe. Gel time is defined as the time at which the adhesive no longer adheres to the probe. 

Abrasion Resistance. Abrasion is the wearing of material from a rubber surface due to the action of an abrasive surface in contact with and moving with respect to the rubber surface. It is measured under a specified load, at a specified sp d and type of abrasive surface. Laboratory tests may not predict service life, because the many and complex factors affecting abrasion vary greatly from application to application. However, laboratory tests are useful for quality control of rubber products intended for rough service. 

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