HJ 6092019_English: PDF (HJ6092019)
Standard ID  Contents [version]  USD  STEP2  [PDF] delivered in  Standard Title (Description)  Related Standard  Status  Google Book 
HJ 6092019  English  349 
Add to Cart

Days<=4

Technical specifications and test procedures for water quality online automatic monitoring equipment of chromium (VI)

HJ 6092019
 Valid 
HJ 6092019

Standard ID  HJ 6092019 (HJ6092019)  Description (Translated English)  Technical specifications and test procedures for water quality online automatic monitoring equipment of chromium (VI)  Sector / Industry  Environmental Protection Industry Standard  Word Count Estimation  15,184  Date of Issue  12/24/2019  Date of Implementation  3/24/2020  Older Standard (superseded by this standard)  HJ 6092011  Drafting Organization  China National Environmental Monitoring Station  Administrative Organization  Ministry of Ecology and Environment 
S xx
n
(2)
SLOQ 10 (3)
In the formula. S7 standard deviation of measured value, mg/L;
nnumber of measurements;
ixthe ith measured value, mg/L;
xaverage value of standard solution measurement, mg/L;
LOQlower limit of quantification, mg/L.
5.5.3 Precision
The instrument measures a standard solution with a concentration value of 50% of the upper limit of the detection range. It measures 6 times continuously and calculates the phase of the 6 measured values.
Regarding the standard deviation, the relative standard deviation is used as the determination value of precision. The calculation method is shown in formula (4).
7
00% 1
xx
(4)
In the formula. Srprecision of the instrument,%;
nnumber of measurements;
ixthe ith measured value, mg/L;
xThe average value of the measured value of the standard solution, mg/L.
5.5.4 Zero drift
A standard solution with a concentration value of the lower limit of the detection range is used for continuous measurement for 24 hours. The average value of the previous three measurements is
Initial measurement value, calculate the percentage of the maximum change between the subsequent measurement value and the initial measurement value with respect to the upper limit of the detection range
rate. The calculation method is shown in formulas (5) and (6).
Number of data. a total of 24 x1, x2, x3x24.
I i iZ x C (5)
100%
ΔZ
ZD max (6)
In the formula. iZabsolute error of the ith measured value relative to the standard solution concentration value, mg/L;
ixthe ith measured value, mg/L;
Cinitial measured value of standard solution, mg/L;
ZDzero drift of the instrument,%;
maxZthe maximum value of the absolute error of the ith measured value relative to the standard solution concentration value, mg/L;
AUpper limit of detection range, mg/L.
5.5.5 Span Drift
A standard solution with a concentration value of 80% of the upper limit of the detection range is used for continuous measurement for 24 hours, and the average of the previous three measurements is taken.
Is the initial measurement value, and calculates the percentage of the maximum change between the subsequent measurement value and the initial measurement value with respect to the upper limit of the detection range
rate. The calculation method is shown in formulas (7) and (8).
(9)
In the formula. Vrelative error caused by voltage change,%;
Xaverage value of 3 measurements under the working voltage of 242 V, mg/L;
Wthe average value of 3 measurements under the initial voltage of 220 V, mg/L;
YThe average value of 3 measurements under the working voltage of 198 V, mg/L.
5.5.7 Ambient temperature stability
Place the instrument in a constant temperature room and measure a standard solution with a concentration value of 80% of the upper limit of the detection range.
Measurement results after 5 h at 5 ° C, 20 ° C, 40 ° C, and 20 ° C for 3 h. 3 times of measured value at 20 ℃
The average value is a reference value, and the relative error between the first measurement value and the reference value under the conditions of 5 ° C and 40 ° C is calculated according to formula (10).
Difference, take the maximum value of relative error as the judgment value of the stability of the instrument's ambient temperature. See calculation formula (10).
1 100%
t X XW
And 2 100%
t X XW
(10)
Where. tWenvironmental temperature stability,%;
The first measurement value at 1X 5 ℃, mg/L;
Xthe average value of three measurements at 20 ° C, mg/L;
2Xthe first measurement under 40 ℃, mg/L.
5.5.8 Ion interference
Mix the interference ions specified in Table 2 into mixed interference ions and add them to the standard solution. After adding, in the mixed solution
The concentration of interfering ions should meet the requirements of Table 2. The concentration of hexavalent chromium ions is 50% of the upper limit of the detection range. Instrument continuous measurement
Measure the hexavalent chromium ion concentration of the mixed solution three times, calculate the indication error of the three m
