Aralkree Measured values are given according to your official product specifications e. Historical Version s — view previous versions of standard Translated Version s: This enables a xed measuring time to be written in to the experimental protocol. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. Discover the gold at the bottom of the barrel.
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Aralkree Measured values are given according to your official product specifications e. Historical Version s — view previous versions of standard Translated Version s: This enables a xed measuring time to be written in to the experimental protocol. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
Discover the gold at the bottom of the barrel. Dec 21 Read NOTE atsm experience using the instrument, the user will be able to judge with a safe margin the amount of time needed for a sample to thermally equilibrate on the prism. Last previous edition adtm in as D — Any out satm control data should trigger an investigation of root cause s.
Filters can be used to eliminate unwanted lines borderlines. However, for practical purposes, because of the proximity of the lines, it is regarded as a single wavelength source and the average value of A number in parentheses indicates the year of last reapproval.
The tester contains all required components ac The accuracy and resolution of the temperature measuring device shall be 0. The protocol should also include procedures that govern the control of calibration materials: Allow 3 min temperature equilibration time. Mercury, or its vapor, may be hazardous to health and corrosive to materials.
Test plates are particularly difficult to apply to sapphire prisms of the type typically used in digital electronic refractometers. The temperature control unit external atsm internal shall have the following control specication: Check that the prism temperature is within 0. Caution should be taken when handling mercury and mercury containing products. Instrument software can be used to compensate for and thus minimize this error source but it will nevertheless be a factor in determining the limiting accuracy of the instrument.
Lower the sample presser if tted. It may also be dened as the sine of the angle of incidence divided by the sine of the angle of refraction, as light passes from air into the substance. NOTE 3—Measurement of refractive dispersion requires more than one type of light source. The dispersion error will however differ according to the substance measured.
Do not dry the prism faces by rubbing with dry cotton. Make your daily measuring routine a piece of cake: An upward drift means the sample is cooling on the prism; a downward drift means the sample is warming up.
A light reection mechanism has the advantage that effects of absorption highly colored samples are minimized. Originally approved in This is the relative index of refraction. Verification of the accuracy of such measurements will depend upon the availability of reliable, certified reference standards that demonstrate the performance of the instrument used under the particular measuring conditions.
The relative change in refractive index with temperature temperature coefficient is different for each liquid under test. Reagents and Materials Warning—2,2,4trimethylpentane, methylcylcohexane, and toluene are all ammable. Solid plates are often preferred for their stability shelf lifebut have the disadvantage of limited accuracy in use because of the errors associated with the placing of the plate on the refractometer prism.
NOTE 9—When successive readings are drifting, the direction of drift will indicate what is happening to the sample. To leave comments please complete the form below. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.
In circumstances where the instrument is used continuously and in a constant thermal condition, the need for recalibration should be minimal. A wide range of sample filling units and measuring modules can be added at a later date, making the Modulyser Unlimited class fit for future requirements. Most Related.
ASTM D1218 PDF
Mikataxe Other light sources include mercury, cadmium, helium, and hydrogen where lters are used with the refractometer to eliminate unwanted emission lines. Benefit from extensive experience in petroleum testing technology. The temperature control unit external or internal shall have the following control specication: A wide range of sample filling units and measuring modules can be added at a later date, making the Modulyser Unlimited class fit for future requirements. No other units of measurement are included in this standard. Report the calculated value and the test temperature, for example: Warning—Volatile hydrocarbon samples are ammable. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. Thoroughly clean the prism faces with toluene, 2 6.
ASTM D1218 - 12(2016)