Designation:D7220 ? 12 (Reapproved 2017)

Standard Test Method for

Sulfur in Automotive, Heating, and Jet Fuels by Monochromatic Energy Dispersive X-ray Fluorescence Spectrometry

用單色能量色散x射線熒光光譜法測(cè)定汽車燃料、加熱燃料和噴氣燃料中硫的標(biāo)準(zhǔn)試驗(yàn)方法

1.Scope

1.1 This test method specifies an energy-dispersive X-ray fluorescence (EDXRF) method for the determination of total sulfur in automotive, No. 2 heating, and jet fuels with a concentration range of 3 mg ?kg to 942 mg ?kg.

1.1.1 The pooled limit of quantitation of this test method as obtained by statistical analysis of inter laboratory test results is 3 mg ?kg sulfur.

1.1.2 This test method is applicable to gasoline, oxygen enriched gasoline (RFG), diesel, diesel/biodiesel blends con- taining up to twenty volume percent biodiesel, kerosene, jet fuel, jet fuel/biodiesel blends containing up to five volume   percent biodiesel and No. 2 home heating oil.

1. 范圍

1.1 本試驗(yàn)方法規(guī)定了用于測(cè)定3 mg/kg至942 mg/kg濃度范圍內(nèi)汽車燃料、2號(hào)加熱燃料和噴氣燃料中總硫的能量色散X射線熒光（EDXRF）法。

1.1.1 通過(guò)實(shí)驗(yàn)室間試驗(yàn)結(jié)果的統(tǒng)計(jì)分析獲得的本試驗(yàn)方法的總定量限為3 mg/kg硫。

1.1.2 本試驗(yàn)方法適用于汽油、富氧汽油（RFG）、柴油、含20%生物柴油的柴油/生物柴油混合物、煤油、噴氣燃料、含5%生物柴油的噴氣燃料/生物柴油混合物和2號(hào)家用取暖油。

15.2 The precision of the test method is as follows:

15.2.1 Repeatability—The difference between successive test results obtained by the same operator with the same apparatus under constant operation conditions on identical test material would, in the long run, in the normal and correct   operation of the test method, exceed the value:

15.2 試驗(yàn)方法的精度如下：

15.2.1 重復(fù)性—從長(zhǎng)期來(lái)看，在試驗(yàn)方法的正常和正確

操作中，同一操作員在相同試驗(yàn)材料上使用相同儀器在恒定操作條件下獲得的連續(xù)試驗(yàn)結(jié)果之間的差值，20個(gè)結(jié)果中只有1個(gè)結(jié)果，將超過(guò)以下值（見(jiàn)表3）：

0.6430·X^0.504mg/kg   (5)

where:

X   =  the mean sulfur content of two results between 3 and 942 mg/kg, only in one case in twenty. (See Table 3.)

15.2.2 Reproducibility—The difference between two single and independent results obtained by different operators work- ing in different laboratories on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the value:

那里：

X   = 在3到942 mg/kg 之間的兩個(gè)結(jié)果的平均硫含量。

15.2.2 再現(xiàn)性—從長(zhǎng)期來(lái)看，在試驗(yàn)方法的正常和正確操作中，在不同實(shí)驗(yàn)室對(duì)同一試驗(yàn)材料進(jìn)行操作的不同操作員獲得的兩個(gè)單獨(dú)和獨(dú)立結(jié)果之間的差值，20個(gè)結(jié)果中只有1個(gè)結(jié)果，將超過(guò)以下值（見(jiàn)表4）：

1.1121·X^0.504mg/kg   (6)

where:

X   =  the mean sulfur content of two results between 3 and 942 mg/kg, only in one case in twenty. (See Table 4.)

式中：

X   = 在3到942 mg/kg之間的兩個(gè)結(jié)果的平均硫含量。

TABLE 3，4  Precision Values, All Sample Types

表3，4 精度值（所有樣品類型）

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