ISO-9029-1990.pdf
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1、INTERNATIONAL STANDARD First edition 1990-l 2-l 5 Crude petroleum - Determination of water - Distillation method P to facilitate condenser wash- down, the condensate should be held as close as possible to the condenser outlet). After the initial heating, adjust the rate of boiling so that the conden
2、sate proceeds no more than three-quarters of the distance up the condenser inner tube. Collect the distillate in the trap at a rate of approximately 2 to 5 drops per second. Continue distillation until no water is visible in any part of the apparatus, except in the trap, and the volume of water in t
3、he trap re- mains constant for at least 5 min. If there is a persistent accumulation of water drop- lets in the condenser inner tube, flush with xylene a jet-spray washing tube (5.7) or equivalent device is recommended. It is essential to shut off the heat at least 15 min prior to wash-down to preve
4、nt bumping. The addition to the xylene wash of an oil- soluble emulsion breaker at a concentration of 1000 ppm helps dislodge the clinging water drops. After flushing, redistill for at least 5 min, applying the heat slowly to prevent bumping. Repeat this procedure until no water is visible in the co
5、ndenser and the volume of water in the trap re- mains constant for at least 5 min. If this procedure does not dislodge the water, use the pick or PTFE scraper (5.8), or an equivalent device, to cause the water to run into the trap. 9.5 When the carry-over of water is complete, al- low the trap and c
6、ontents to cool to room temper- ature. Dislodge any drops of water adhering to the sides of the trap with the pick or PTFE scraper and transfer them to the water layer. Read the volume of the water in the trap. The trap is graduated in 0,05 ml increments, but the volume is estimated to the nearest 0
7、,025 ml. 9.6 Carry out a blank determination by placing 400 ml of solvent in the distillation flask and testing as outlined in 9.1 to 9.5. 10 Expression of results Calculate the w ater conten t oft he sample using one of the following exp ression s as appropriate: V V a) ?G (V/V) = *F O x 100 1 b) %
8、 (V/V) = V V 2m-p x 100 v c) O/O (m/m) = - vo 2 112 x 100 where vo VI 5 m P is the volume, expressed in millilitres, of water in the trap (rounded to the nearest 0,025 ml) when measurement is made on the solvent blank; is the volume, expressed in millilitres, of the test portion; is the volume, expr
9、essed in millilitres, of water in the trap (rounded to the nearest 0,025 ml); is the mass, expressed in grams, of the test portion; is the density, expressed in grams per millilitre, of the sample. It is assumed that the density of water is 1 g/ml. Volatile water-soluble material, if present, may be
10、 measured as water. Report the result as the water content rounded to the nearest 0,025 %. 11 Precision The precision of the method as obtained by statis- tical examination of inter-laboratory test results in the range from 0,Ol % to I,0 % is as follows: 11.1 Repeatability The difference between suc
11、cessive test results ob- tained by the same operator with the same appara- tus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the following values in only one case in twenty: from 0,O % ( V/v) to 0
12、,l % ( V/v) water: see figure 3; from 0,l % (L/I/) to I,0 % (V/v) water: 0,08 % (?/V)- 11.2 Reproducibility The difference between the two single and inde- pendent results obtained by different operators working in different laboratories on identical test material would, in the long run, in the norm
13、al and correct operation of the test method, exceed the following values in only one case in twenty: from 0,O % (V/v) to 0,1 % (V/V) water: see figure 3; 4 IS0 9029:1990(E) from 0,l % (V/v) to I,0 % (V/V) water: b) a reference to this International Standard; 0,ll % (V/v). c) the result of the test (
14、see clause IO); 12 Test report d) the individual results for each test portion, if more than one test portion is examined (see 8.3); The test report shall contain at least the following information: e) any deviation, by agreement or otherwise, from the procedure specified; a) all details necessary f
15、or the identification of the product tested; f) the date of the test. IS0 9029:1990(E) Dimensions in millimetres -J .- IfI I JV -I II1 y/ 17 v 35 0 F7 lit- 9 a m (v 5 i-0 .- 3 I- i6 5 ml trap yul _1 0 m 7 NI U-J I -/Y-/Y 0,050 6 0,025 Repeatability 7 I I I P 0 0,025 0,050 0,075 0,100 Average water c
16、ontent, 5% (Vl V) Figure 3 - Precision of the method for water contents within the range 0,O % (V/r/) to 0,l % (r/l V) -,-,- IS0 9029:1990(E) Annex A (normative) Sample handlina ma NOTE 2 This annex reproduces the instructions on sample handling from ISO 3170:1988 and IS0 3171:1988, and is essential
17、ly identical with the corresponding clauses therein. A.1 General A.l.1 The method of handling samples between the point at which they are extracted or drawn, and the laboratory test bench or sample storage are de- vised to ensure that the nature and integrity of the sample are maintained. A.l.2 The
18、method of handling a sample will de- pend on the purpose for which it has been taken. The laboratory analytical procedure to be used will often require a special handling procedure to be associated with it. For this reason, consult the ap- propriate methods of test so that any necessary in- structio
19、ns as to sample handling can be given to the person drawing the sample. If the analytical proce- dures to be applied have conflicting requirements, then draw separate samples and apply the appro- priate procedure to each sample. A.1.3 Take particular care in respect of the follow- ing: a) liquids co
20、ntaining volatile material, since loss by evaporation can occur; b) liquids containing water and/or sediment, since separation tends to occur in the sample con- tainer; c) liquids with potential wax deposition, since de- position can occur if a sufficient temperature is not maintained. A.l.4 When ma
21、king up composite samples, take great care not to lose light ends from volatile liquids and not to alter water and sediment content. This is a very difficult operation and should be avoided if at all possible. A.1.5 Do not transfer samples of volatile liquids to other containers at the sampling loca
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