National Metrology Verification Regulation of the People's Republic of China JJG178-2007
Ultraviolet, Visible, Near-Infrared Spectrophotometers2007-11-21Promulgated
Implemented on 2008-05-21
Promulgated by the General Administration of Quality Supervision, Inspection and Quarantine JIG 178--2007
Verification Regulation of Ultraviolet, Visible, Near-Infrared Spectrophotometers
Verification Regulation of Ultraviolet, Visible, Near-Infrared Spectrophotometers JJG 178—2007
Replaces JJG178—1996
JJG 689—1990
JJG 375-1996
JJG 682—1990
This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on November 21, 2007 and will be implemented on May 21, 2008.
Responsible unit: National Technical Committee for Physical and Chemical Metrology Main drafting unit: Heilongjiang Metrology Verification and Testing Institute Additional drafting unit: Shanghai Precision Scientific Instrument Co., Ltd., China National Institute of Metrology
Beijing Puxi General Instrument Co., Ltd. This regulation is entrusted to the National Technical Committee for Physical and Chemical Metrology for interpretation Main drafter of this regulation:
JJG 178—2007
Ye Jun'an (Heilongjiang Metrology Verification and Testing Institute) Additional drafter!
Li Luming (China Academy of Planning and Design Sciences) Li Zheng (Shanghai Precision Scientific Instrument Co., Ltd.) Sun Hongwei (Beijing Puxi General Instrument Co., Ltd.) 1
References·
wwW.bzxz.NetMetrological performance requirements
Maximum allowable error of wavelength,
Repeatability of measured length
Noise and shift
Minimum spectral bandwidth·
Maximum allowable error of transmittance:
Repeatability of transmittance·
Baseline straightness
4.8 Adaptability of power supply voltage
Stray light
Suitability of absorption cell
5 General technical requirements
5.1 Safety performance
5.2 Marking·
5.4 Absorption cell·
6 Control of measuring instruments·
6. 1 Verification conditions
6.2 Verification items
6.3 Verification methods
6.1 Processing of verification results·
6. 5 Verification period·
Appendix A Test wavelength of wavelength standard material
JJG 178—2007
Transmittance ratio of potassium dichromate standard solution at different temperatures and different spectral bandwidths at corresponding wavelengths Appendix
Appendix C Preparation method of standard solution
Appendix D Format of the inner page of the verification certificate
Appendix E Verification record format for ultraviolet, visible and near-infrared spectrophotometers (1)
(2)
(4)
1 Scope
JJG 178—2007
Verification Procedure for Ultraviolet, Visible and Near Infrared Spectrophotometers This procedure is applicable to the initial verification, subsequent verification and in-use inspection of visible, ultraviolet-visible and ultraviolet-visible-near infrared spectrophotometers with a wavelength range of 190nm to 2600nm and continuously adjustable wavelength. 2 References
This procedure refers to the following documents:
International Organization for Legal Metrology (OIML) International Recommendation R135 "Spectrophotometers for Medical Laboratories" (International recommendation OIML Rl35 Edition 20o4 Spectrophotometers for medical laboratories) JJF1001—1998 General metrological terms and definitions" JF1059—1999 Evaluation and expression of measurement uncertainty) When using this procedure, attention should be paid to using the current valid versions of the above-mentioned references. 3 Overview
UV-visible-near-infrared spectrophotometer (hereinafter referred to as the instrument) is an instrument for quantitative analysis and qualitative identification of substances based on the selective absorption of the molecules of substances to ultraviolet, visible and near-infrared radiation (light) and the Lambert-Beer law.
The mathematical expression of the Lambert-Beer law is: A -lg/,> =- gT - ktc
Where: A——absorbance of the substance,
I.—incident monochromatic light intensity,
I——transmitted monochromatic light intensity;
T—radiation avoidance ratio of the substance,
T——absorption coefficient of the substance
tThe optical path of the substance being analyzed;
The degree of the substance.
The instrument is mainly composed of a light source, a monochromator, a sample chamber, a detector, a signal processing and display and storage system. 4 Metrological performance requirements
To facilitate the description of metrological performance requirements, the working wavelength of the instrument is divided into three sections, namely Section A (190nm~340nm), Section B (340nm~900nm), and Section C (900nm~2600nm). According to the metrological performance, the instrument is divided into four levels: I, II, II, and I. 4.1. Maximum allowable wavelength error
The maximum allowable wavelength error of the instrument shall meet the requirements of Table 1. 1
Wavelength repeatability
JJG 178—2007
Maximum allowable wavelength error
The wavelength repeatability of the instrument shall meet the requirements of Table 2. Wavelength repeatability
Noise and drift
The noise and drift of the instrument shall meet the requirements of Table 3. Section B
Noise and drift requirements
The transmittance is 0% noise
Note: Non-scanning instruments are not used as indicators. 4.4 Minimum spectral bandwidth
The transmittance is 100% noise
The minimum spectral bandwidth error of the instrument shall not exceed ±20% of the nominal spectral bandwidth. 4.5 Maximum allowable error of transmittance
The maximum allowable error of transmittance of the instrument shall meet the requirements of Table 4. 4.6 Transmittance repeatability JJG178-2007 The instrument transmittance repeatability shall meet the requirements of Table 5. Table 5 Transmittance repeatability Baseline straightness Instrument baseline straightness absorbance expression shall meet the requirements of Table 6. 4.8 Adaptability of power supply voltage When the power supply voltage fluctuation is (220±22)V, the baseline straightness meets the requirements.
The change of the transmittance indication of the instrument shall meet the requirements of Table OH
Adaptability of power supply voltage
Change of transmittance indication
METROLOGY
4.9 Stray light
The stray light of the instrument shall meet the requirements of Table 8
Table 8 Stray light
1420nm
4.10 Matching of absorption cell
The matching of absorption cell shall meet the requirements of Table 9.
JJG 178—2007
Table matching requirements
Absorption cell category
General technical requirements
5.1 Safety performance
The insulation resistance of the instrument shall not be less than 20 mA. 5.2 Marking
Matching error
The instrument should have the following markings: name, model, number, manufacturer name, date of manufacture, working power supply voltage, frequency. Domestic instruments should have the production license mark and number. 5.3 Appearance
All fasteners of the instrument should be well tightened, all adjustment knobs, buttons and switches can work properly, the connectors of the cable can fit tightly and be well grounded
The instrument should be able to be placed stably on the workbench + the sample rack should be positioned correctly. The thickness of the indicator scale is uniform and clear, the digital display is clear and complete, the adjustable parts should not have jamming, sudden jumps and significant empty return,
5.4 Absorption cell
The absorption cell should not have cracks, and the light-transmitting surface should be clean, without scratches and spots. 6 Control of measuring instruments
Control of measuring instruments includes initial verification, subsequent verification and inspection during use. 6.1 Verification conditions
6.1.1 Wavelength standard material
6.1.1.1 Mercury lamp
6.1.1.2 Iron oxide with standard wavelength values at three spectral bandwidths of 1, 2, and 5 Ⅱ m, and mis-sensitive and mis-bait filters6. 1. 1.3±
Titanium oxide solution, mass expansion is 40g/L! 6.1.1.41.2,4-Trifluorobenzene (analytical grade) #6. 1. 1. 5
Interference filter: peak wavelength standard uncertainty ≤1nm, spectral bandwidth 15nm. 6. 1. 2 Transmittance standard substance
6.1.2.1 0.001ml/L perchloric acid standard solution with a mass fraction of 0.06000/1000 potassium dichromate, 6.1.2.2 Ultraviolet light region transmittance filter 16.1.2.3 Spectral neutral filter, the nominal transmittance value is 10%, 20%, 30%. 6.1.3 Stray light source
Cut-off filter, the cut-off wavelength is 220, 360, 420nm, the half-height cut-off wavelength is 260, 400, 47nm, the cut-off wavelength is not less than 225, 365, 430nm, the absorbance in the cut-off area is not less than 3, and the average transmittance in the light-bearing area is not less than 80%;
6.1.3.2 Sodium iodide standard solution, the concentration is 10.0 g/L6.1.3.3 Sodium nitrite standard solution, the concentration is 50.0g/L. 6.1.4 Standard quartz absorption cell: the specification is 10.0 mm, and the transmittance matching error is not more than 0.2%. 6. 1.5 Calibration equipment
6.1.5.1 Voltage regulating transformer, withdrawal power not less than 500W, output voltage (～250)V, megohmmeter: test voltage 500V, level 10
Multimeter: not less than level 2.5;
6. 1.5. 3
6.1.5.4 Stopwatch: division value not greater than 0.1s. 6.1.6 Environmental conditions
6.1.6.1 Temperature, (10~~35)C:
Relative condensation not more than 85%
6.1.6.2
6.1.6.3 Power supply: voltage is (220±22)V, frequency is (50±1)Hz, 6.1.6.4 The instrument should not be exposed to direct strong light, strong magnetic field, electric field interference, strong airflow and corrosive gas. 6.2 Verification items
The initial verification, subsequent verification and in-use inspection items of the instrument are shown in Table 10. 10. Overview of verification items
Verification items
General technical requirements
Wavelength indication error and repeatability
Noise and source
Spectral bandwidth
Transmittance indication error and repeatability
Baseline flatness
Suitability of power supply voltage
Stray light
Suitability of collection cell
Preliminary requirements
Note: "*" means items to be inspected, "-" means items that may not be inspected. 6.3
Verification method
6.3.1 Inspection of general technical requirements
6.3.1.1 Safety performance
Subsequent verification
In-use inspection
Use a 500 megohmmeter to measure the insulation resistance between the power input terminal and the casing (or grounding terminal) of the instrument. During the test, the power plug is not connected to the power grid, the power switch is in the on position, the phase line and the neutral line of the power plug are short-circuited with a wire, and the megohmmeter is used to read the insulated resistance between the phase line of the power plug and the grounding terminal of the instrument. 6.3.1.2 Appearance, marking and absorption cell
According to the requirements of 5.2~5.4, self-inspection, manual inspection, 5
JJG178—2007
6.3.2 Wavelength Maximum allowable error and wavelength repeatability Ultra-small wonton bucket broadband
6.3.2.1 Selection of standard substances
Tools
Select standard substances according to the instrument, see Table 11. The standard substances available are: ① low-pressure quartz mercury lamp, ② iron oxide filter, ③ iron oxide solution, ① standard interference filter, 5-zirconium neodymium filter, ③ zirconium filter, ?1,2,4-trichlorobenzene (analytical grade), 8-instrument gas lamp, ?high-pressure mercury lamp.
Table 11 Selection of wavelength standard
[email protected], 5,6
According to the working wavelength range of the instrument, correctly select the measuring wavelength. Section A
One wavelength calibration point
Long calibration point.
Section B According to the wavelength range of the instrument, refer to Appendix 6.3.2.2 Calibration steps
a) Non-automatic scanning instrument
Section B At least select
A.1.A.4 at every 100nm interval, at least five wavelengths are selected
When using solution or active light film standard substances, select the instrument's transmittance or absorbance measurement mode, use air as the air at the measured wavelength point to adjust the instrument's transmittance to 100% (0A), insert Adjust the transmittance to 0% with the light shield, then place the standard material vertically in the sample light path to read the photometric value of the standard material, repeat the above steps to measure the transmittance or absorbance of the standard material at a point near the wavelength calibration point, calculate the corresponding transmittance value or absorbance peak wavelength, and measure continuously for 3 times.
When selecting a mercury lamp, place the mercury lamp in the light source room so that the light of the mercury lamp is incident on the monochromator slit, select the energy measurement method of the instrument, set the appropriate gain, adjust the position of the recording lamp so that the energy value reaches the maximum, and then measure the peak wavelength corresponding to the energy maximum value point by point near the peak wavelength in a single direction, record, and measure continuously. b) Automatic scanning instrument
According to the selected calibration wavelength, set the wavelength scanning range of the instrument (if the wavelength scanning range is wide, segmented scanning is allowed), the commonly used spectral bandwidth, and the sampling interval of the wavelength repeatability index of the slow scanning instrument (if the wavelength sampling interval cannot be set, a slower scanning speed should be selected. When using lubricant or filter standard substances, adopt the transmittance or absorbance measurement method, use air as a blank to calibrate the instrument's baseline according to the set scanning parameters, use a light shield to calibrate the dark current, and then place the standard substance vertically in the sample light path, set a suitable recording range, scan continuously for 3 times, and detect (or measure) the transmittance valley value or absorbance peak wavelength respectively. When using a low-pressure quartz mercury lamp, scan continuously for 3 times according to 6.3.2.2a), and detect (or measure) the peak wavelength of energy respectively. 6.3.2.3 Result calculation Calculate the wavelength indication error for each measured wavelength according to formula (1): M-XA (1) Where: 一一 is the average value of 3 measurements, 一一 is the wavelength standard value. Calculate the wavelength repeatability according to formula (2): 一一 is the average value of 3 measurements, 一一 is the wavelength standard value. Calculate the wavelength repeatability according to formula (2): 一一 is the average value of 3 measurements, 一一 is the wavelength standard value. 6.3.2.3 Result calculation Calculate the wavelength indication error for each measured wavelength according to formula (1): M-XA (1) Where: 一一 is the average value of 3 measurements, 一一 is the wavelength standard value. Calculate the wavelength repeatability according to formula (2): 一一 is the average value of 3 measurements, 一一 is the wavelength standard value. 6.3.3 Noise and Drift
According to the working band range of the instrument, select 250nm in section A, 500nm in section B, and 1500nm in section C as the measurement wavelengths of noise, and 500nm as the measurement wavelength of drift. Set the scanning parameters of the instrument to overshoot scanning (HS or variable length scanning), spectral bandwidth 2nm (not set for instruments with fixed spectral bandwidth), time sampling interval (or integration time), photometric measurement method is transmittance, recording range 99%~101% (not set for medium scanning instruments), treat the reference beam and sample beam as air blanks at each measurement wavelength, adjust the instrument's transmittance to 100%, scan for 2 minutes, and the difference between the maximum and minimum values on the measurement window (for non-scanning instruments, record the maximum and minimum values within 2 minutes), which is the instrument's transmission ratio of 100%. Insert a block in the sample light path, adjust the instrument's transmittance to 0%, scan for 2 minutes, and measure the difference between the maximum and minimum values on the graph (for non-scanning instruments, only record 2 minutes). min) is the instrument transmittance 0% noise. When switching wavelengths, allow the light to stabilize for 5
Medical Wide New Water Home
Automatic scanning receiver, test the transmittance 0% and 100% noise according to the above requirements, set the cover at 500nm, and read the difference between the maximum and minimum values of the center line of the scanning spectrum envelope line, which is the instrument's transmittance scanning 30min
100% line drift
6.3 .4 Minimum spectral bandwidth
Jinshi Iron
For instruments with a permissible lamp, select the 656.1nm characteristic spectrum line of the chrysogen lamp. For instruments without a chrysogen lamp, select the 546.1nm (or 253.7nm) characteristic spectrum line of the mercury lamp. Select the minimum spectral bandwidth and record the characteristic spectrum line graph of the chrysogen lamp or mercury lamp according to method 2.2. The measured half-peak width is the minimum spectral bandwidth. 6.3.5 Maximum allowable error and repeatability of transmittance New
6.3.5.1 Verification steps
a) Use the standard substance and standard absorption cell in 6.1.2 to measure the transmittance three times at 235, 257, 313, and 350 nm respectively.
You can also use the ultraviolet transmittance filter in 6.1.2.2 for measurement. b) Use a neutral density filter with a transmittance value better than 20% and 30% of the nominal value to measure the transmittance at 440, 546, and 635 nm respectively, with air as the reference. 6.3.5.2 Result calculation 5
Calculate the transmittance indication error according to formula (3):
Where: T-the average value of 3 measurements:
T standard transmittance value.
Calculate the transmittance repeatability according to formula (4)
Middle East Commercial and Industrial Classics
TT-T combination 3)
National Limited Decoration
In the formula, mx, T-the maximum and minimum values of the transmittance measured 3 times. Jinpin Erjie-Mingyanhui (4)
6.3.6 Baseline Straightness
JJG178-2007
After the baseline calibration is carried out according to the instrument requirements, set the instrument spectral bandwidth to 2ntm (no spectral band adjustment block is required for instruments without spectral band adjustment block), the scanning speed to medium speed, the sampling interval to 1nm, and set the appropriate absorbance measurement range according to the instrument manual. Scan at the wavelength lower limit plus 10nm and the wavelength upper limit minus 50nm. The difference between the absorbance at the starting point in the spectrum and the absorbance deviating from the starting point (taking the maximum deviation point) is the baseline flatness (a momentary jump is allowed when the light source or receiver is replaced).
6.3.7 Adaptability of power supply voltage
Use a voltage regulator to input 220V voltage, and adjust the transmittance indication to 100% at the selected wavelengths of 250, 500, and 1500nm. Change the input voltage and record the transmittance indication of the instrument at 198V and 242V respectively. Calculate the difference from 100% and it is the adaptability of the power supply voltage. 6.3.8 Stray light
Select the standard substance for stray light measurement specified in 6.1.3, and measure the transmittance of the standard substance at the corresponding wavelength. Its transmittance value is the stray light of the instrument at this wavelength. a) For section A, use sodium iodide standard solution (or cutoff filter) at 220nm, sodium nitrite standard solution (or cutoff filter) at 360nm (tungsten lamp), 10nm standard quartz absorption cell, distilled water as reference, and optical harmonic bandwidth 2nm (not set for instruments without spectral bandwidth adjustment). b) For the B-stage mirror instrument, use a cut-off filter to measure the transmittance value at a wavelength of 420 nm with air as the reference.
c) For the C-stage instrument, use Hz0 at a wavelength of 1420 nm to measure its transmittance indication with air as the reference. d) When the low stray light value of the instrument needs to be measured, use an attenuation plate, first measure the attenuation value of the attenuation plate, and then use the attenuation plate as the reference to measure the transmittance value of the above-mentioned standard material. The product of the two transmittance values is the stray light. 6.3.9 Matching of absorption cells
In the absorption cells with the same optical path attached to the instrument, fill distilled water at 220nm (quartz absorption cell) and 440nm (glass absorption cell), adjust the transmittance of one absorption cell to 100%, measure the transmittance value of the other guest cells, and the difference is the matching of the absorption cell.
For instruments with a transmittance range of only 0-~100%, 95% can be used instead of 100%. 6.3.10 For other types of spectrophotometers whose measurement methods are not fully included in the scope of this regulation, their main technical indicators can be calibrated with reference to the above-mentioned calibration methods, and the technical requirements can be in accordance with the factory technical indicator requirements of the instrument. 6.4 Handling of calibration results
6.4.1 Newly manufactured instruments should be fully calibrated according to the initial calibration items in Table 10 of 6.2. Subsequent calibration and in-use inspection should, in principle, be carried out according to the contents of subsequent calibration and in-use inspection in Table 10, and if necessary, according to the initial calibration requirements.
6.4.2 For instruments that have passed the calibration according to this regulation, a calibration certificate shall be issued, and the instrument qualification level shall be indicated with the lowest level in the calibration results: If one of the indicators in the virtual inspection items (excluding 4.10) does not meet the requirements, it shall be judged as unqualified, and a calibration result notice shall be issued, indicating the unqualified items. 6.5 Calibration cycle
The calibration cycle is generally not more than 1 year. During this period: when the instrument is repaired or there is doubt about the measurement results, it should be calibrated in time.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.