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MVRRCNG0163 Verification Procedure for Ultraviolet, Visible and Near Infrared Spectrophotometers 1. Verification Procedure for Ultraviolet, Visible and Near Infrared Spectrophotometers Description Number
Responsible Unit
Drafting Unit
Main Drafters
Approval Date
Implementation Date
Alternative Procedure Number
Scope of Application
Main Technology
Whether Classified
Verification Period (Year)
Number of Appendixes
Publishing Unit
Verification Standard Materials
Related Technical Documents
JJG689-1990
(Chinese) Ultraviolet Verification Regulation of UV-VIS-NIR Spectrophotometer National Research Center for Standard Materials
National Research Center for Standard Materials
Yang Rujun (National Research Center for Standard Materials)June 8, 1990
October 1, 1990
This regulation applies to the verification of fixed, movable and portable combustible gas detection alarms (hereinafter referred to as instruments) that are newly manufactured, in use and after repair. 2
Wavelength accuracy and wavelength repeatability
3Resolution or minimum spectral bandwidth
4Stray radiance
5Transmittance accuracy and transmittance repeatability
6Baseline flatness
7Drift
9Insulation resistance
China Metrology Press
2.Verification Procedure for Ultraviolet, Visible and Near-infrared SpectrophotometersAbstractOverview
Ultraviolet, visible and near-infrared spectrophotometers (hereinafter referred to as instruments) are instruments that perform qualitative identification and quantitative analysis on substances based on the characteristics of the absorption spectrum of substances in the ultraviolet, visible and near-infrared regions and the principle of Lambert-Beer's law. The mathematical expression of Lambert-Beer's law is A=lgΦo/Φu=-lgt=ebc
Wherein: A—absorbance of the substance;
do—incident radiation (light) flux (W);
transmitted radiation (light) flux (W):
transmittance of the substance:
molar absorption coefficient of the substance (L/cm·mol): optical path length (cm or mm);
molar concentration of the substance (mol/L);
This type of instrument mainly consists of 5 parts: light source, monochromator, sample chamber, detector and display system. Calibration items and technical requirements
1 Appearance
1.1 The instrument should have a nameplate with the instrument name, model, number, manufacturer name and power supply voltage indicated. 1.2 The instrument should have an instruction manual. Newly manufactured instruments should have a factory inspection certificate: calibrated instruments should be accompanied by the last calibration certificate.
1.3 The instrument should be able to be placed stably on the workbench, all fasteners should not be loose, and the connectors should fit tightly and have good contact. 1.4 All lettering and engravings on the instrument should be uniform and clear, and the digital display should not have defects or missing pictures. All switches, regulators and buttons on the instrument should be able to work normally: the image on the fluorescent screen should be clear and the brightness should be adjustable. 1.5 There should be no light leakage in the sample chamber.
1.6 There should be no abnormal noise after the instrument is started, and it should be able to work normally after preheating for 30 minutes. 2 Wavelength accuracy and wavelength repeatability
The wavelength accuracy and wavelength repeatability of the instrument shall comply with the provisions of Table 1. Table
Instrument level
Wavelength range
Ultraviolet-visible
Near infrared
Ultraviolet-visible
Near infrared
3 Resolution or minimum spectral bandwidth
Accuracy
Prism
3.1 Resolution shall comply with the provisions of Table 2.
Instrument level
Grating
Prism
Grating
Grating
3.2 Minimum spectral bandwidth:
The minimum actual bandwidth of the instrument shall not be greater than 1.2 times the actual set bandwidth. 4 Stray radiation rate
The ratio of the instrument's stray radiation to the main radiation, that is, the stray radiation rate, shall comply with the provisions of Table 3. Table 3
Instrument level
Transmittance accuracy and transmittance repeatability
Wavelength input (nm)
The transmittance accuracy and transmittance repeatability of the instrument shall comply with the provisions of Table 4. Table 4
Instrument level
Baseline straightness
Accuracy
The baseline straightness of the instrument shall comply with the provisions of Table 5. Table 5
Instrument level
The drift of the instrument shall comply with the provisions of Table 6. Table 6
Instrument level
Wavelength range (nm)
Ultraviolet-visible
Near infrared
Ultraviolet-visible
Near infrared
Ultraviolet-visible
Near infrared
Measurement wavelength (nm)
Instrument noise shall comply with the provisions of Table 7.
Insulation resistance
Insulation resistance is not less than 20MQ.
Measurement time (min)
Stray radiation rate TR (%)
Repeatability
Drift (A)
Instrument level
Measurement wavelength (nm)
230 (or 340)
230 (or 340)
230 (or 340)
10 Power supply and environmental conditions
100% line (A)
Verification conditionswww.bzxz.net
10.1 Power supply: voltage change is not more than 220±22V; frequency change is not more than 50±1Hz. 10.2 Room temperature 15~30℃.
10.3 Environmental relative humidity is less than 85%
10.4 The instrument is not exposed to direct sunlight.
10.5 There should be no strong airflow and corrosive gas in the room. 10.6 There should be no strong vibration and strong electric and magnetic fields that may affect the calibration. 11 Main calibration equipment and materials
11.1 Balance (weighing 200g, graduation value 0.1mg). 11.2 Megaohmmeter (500V).
11.3 Light shield (12×12×45mm opaque rectangular block). 11.4 Attenuation sheet (1/100:10/100). 12 Standard substances* and chemical reagents
0% line (%T)
12.1 Low-pressure mercury lamp: iron oxide glass (thickness 2~2.5mm): benzene (secondary); 1,2,4-trichlorobenzene (third grade). 12.2 Neutral filters with nominal transmittance of about 10%, 20%, and 30% (the uncertainty of the standard value is better than 0.2%).
12.3 Potassium dichromate UV spectrophotometry standard solution with a mass fraction of 0.06000/1000 (the uncertainty of the standard value is better than 0.3%t): UV-visible spectrophotometry standard solution. 12.4 Standard quartz absorption cell (standard material number GBW13304). 12.5 Sodium iodide and sodium nitrite (secondary): methylene blue and dibromomethane (third grade). *After the state approves and promulgates the corresponding standard materials, they should be adopted immediately. 1 Verification method
13 Appearance
Perform according to the requirements of Article 1. Verify the following items after the instrument is turned on and preheated for 30 minutes. 14 Wavelength accuracy and repeatability
14.1 Verify with a low-pressure mercury lamp. Turn off the instrument light source and place the mercury lamp at the entrance slit. Use wavelength scanning (or repeated scanning) mode, slow scanning speed (such as 15nm/min), fast response, minimum bandwidth (such as 0.1nm), range 0~100% (or set conditions according to the instrument manual), repeat scanning in one direction for 3 times within the range of 200~2500nm, and let the instrument identify and record each peak*. Measure the wavelengths of two spectral lines in the three bands of ultraviolet, visible and near-infrared on the spectrum respectively (prism-type instruments should be carried out according to the requirements of Table 1), compare with Table 1 in Appendix 1, and calculate the wavelength accuracy 4x according to formula (2): A=,
Where: — average value of wavelength measurement;
, wavelength standard value.
Calculate the wavelength repeatability 8x according to formula (3):
5=λmax—λmin
Where: Amax, min—
The maximum and minimum values of the wavelength measured three times. 14.2 If the instrument cannot be placed with a low-pressure mercury lamp, the following method is used for partition calibration. 14.2.1 Ultraviolet and visible region
(1) Use the instrument's inherent allowable lamp for calibration. Use the single beam energy mode and the measurement conditions are in accordance with 14.1 (or set the conditions in the instrument manual) for 486.02 and 656.Repeat the single-direction scanning three times for the two single peaks of 10nm, measure the wavelengths of the two spectral lines on the spectrum, compare with Table 2 in Appendix 1, and calculate 4 and 6 according to formulas (2) and (3). (2) Verification using iron oxide glass. The measurement conditions are the same as those in 14.1, with a range of 0 to 2 (A). Place the iron oxide glass in the sample chamber, use air as a reference, scan in the range of 220 to 660nm, measure the wavelengths of the two spectral lines in the ultraviolet region on the spectrum, and compare with Table 3 in Appendix 1, and calculate 4x and 8x according to formulas (2) and (3). 14.2.2 Near-infrared region
Use 1,2,4-trichlorobenzene for verification. The measurement conditions are the same as those in 14.1. The bandwidth is automatically adjusted by the instrument. The normal scanning speed (e.g. 120nm/min) and the range are 0-2 (A). Scan in the range of 1500-2600nm. Measure the wavelengths of the two spectral lines on the spectrum and compare them with Table 4 in Appendix 1. Calculate 4 and 8 according to formulas (②) and (3). * If the instrument does not have the "peak detection" function, a "single peak" scan should be performed on the specified wavelength. 15 Resolution or minimum spectral bandwidth
15.1 Resolution
The instrument adopts wavelength scanning mode. The measurement conditions are: slow scanning speed (e.g. 15nm/min), fast response (or medium), range 0-100%, and minimum bandwidth. Drop 2 drops of benzene into the bottom of the dry quartz absorption cell and cover it. When the benzene vapor fills the absorption cell space, put in the sample beam. Adjust the transmittance to 100% at 258.9nm and scan in the range of 255-265nm. Calculate the resolution (%T) expressed as the resolution depth D as shown in Figure 1 in Appendix 2. 15.2 Minimum spectral bandwidth
When it is difficult to detect the instrument resolution according to the method in 15.1, this method is used. The instrument adopts the single beam energy mode. The measurement conditions are: minimum bandwidth, slow scanning speed, fast response, appropriate negative high voltage (or set the conditions according to the manual), scan in the range of 655-657nm, and then measure the half width of the instrument's inherent chlorine lamp characteristic spectrum line on the energy-wavelength diagram as shown in Figure 2 of Appendix 2. This is the minimum spectral bandwidth of the instrument. 16 Stray radiation rate
16.1 Take the instrument bandwidth of 2nm, take air as reference at 220nm wavelength, insert 1% (or 10%) attenuation plate* in the sample beam, measure the actual value T1 of the attenuation plate, then move the attenuation plate to the reference beam, and use a 10mm quartz absorption cell with a pairing error less than ±0.2%t, respectively fill it with distilled water and 10g/L sodium iodide aqueous solution, put it in the reference and sample beams, measure the transmittance T2, and calculate the stray radiation rate TR according to formula (4): Tr=TiX T2
16.2 Use 50g/L sodium nitrite aqueous solution, 0.005% methylene blue aqueous solution and dibromotoluene at 340nm, 620nm and 1690nm, respectively detect TI and T2 according to the above method, and calculate TR according to formula (4). *If the stray radiation rate of the instrument is greater than 0.1%, the attenuation plate should not be used. 17 Transmittance accuracy and transmittance repeatability 17.1 Ultraviolet region
The instrument bandwidth is 2nm. Use a set of standard quartz absorption cells to hold blank solution and ultraviolet spectrophotometry standard solution respectively. Measure the transmittance three times continuously at four wavelengths of 235nm, 257nm, 313nm and 350nm, compare with Table 1 in Appendix 3, and calculate the transmittance accuracy according to formula (5):4+:A=1-T,
Where: -- average value of transmittance measurement T -- standard value of transmittance.
Calculate the transmittance repeatability according to formula (6): 8: O, = Tmax-Tmin
Where: Tmax, Tmin
17.2 Visible region
Measure the maximum and minimum values of the transmittance three times (5)
The instrument bandwidth is 2nm, use a set of spectral neutral filters with transmittances of 10, 20, and 30%, and use air as a reference at wavelengths of 440nm, 546nm, and 635nm, respectively, and measure the transmittance three times in a row, compare it with the transmittance standard value of the neutral filter, and calculate △, and 5t according to formulas (5) and (6). When the instrument cannot be calibrated with a neutral filter, it is allowed to use ultraviolet and visible spectrophotometric standard solutions to calibrate the instrument transmittance.
18 Baseline straightness
Set the wavelength to the starting wavelength, take the normal scanning speed, bandwidth 2nm, range ± 0.01 (A) (or the most sensitive gear), the reference and sample beams are blank, and perform full-band or segmented scanning. Measure the difference between the starting point of each segment in the spectrum and the maximum offset, which is the baseline straightness*.
*Instantaneous jumps are allowed at the switching point of the light source and the detector. 19 Drift
After the instrument has been thermally balanced for 2 hours, set the wavelength to 500nm, take the bandwidth 2nm, normal scanning speed, range ± 0.01 (A) (the most sensitive gear), the reference and sample beams are blank, and the time scanning mode (or fixed wavelength scanning) is used. Scan for 0.5 hours and measure the change value of the parallel envelope line of the 0 (A) line on the spectrum. This is the drift of the instrument. 20 Noise
20.1100% Line Noise
Set the wavelength to 230nm (or 340nm), select time scan mode (or fixed wavelength scan), bandwidth 2nm, normal scan speed, range ± 0.01 (A) (most sensitive range block), reference beam and sample beam are both blank, time scan (or fixed wavelength scan), scan for 2min, measure the maximum peak-to-peak difference on the spectrum, which is the 100% line noise of the instrument. According to the above method, detect the noise at the wavelengths of 500nm and 1000nm respectively. 20.20% Line Noise
Take the range ± 0.1%T, put the light shield into the sample beam, and then detect the noise at the wavelength of 500nm according to the method of 20.1.
21 Insulation Resistance
Use a megohmmeter to check the resistance value between the instrument housing and the power supply line. Instruments in use can be exempted from inspection. 22 For other types of ultraviolet, visible, and near-infrared spectrophotometers that are not fully included in the scope of the provisions of this regulation, they can be calibrated in accordance with this regulation, and their technical requirements shall be based on the indicators in the instrument manual. V. Calibration result processing and calibration cycle
23 All the data of the above calibration shall be recorded on the record paper, and the spectrum and printed results shall be attached to the original record. 24 For instruments that pass the calibration, a calibration certificate shall be issued; for instruments that fail the calibration, a calibration result notice shall be issued, and the calibration results of the unqualified items shall be indicated.
25 The calibration cycle of ultraviolet, visible, and near-infrared spectrophotometers is one year. If the instrument is moved, repaired, or if the measurement results are found to be suspicious, it should be calibrated at any time. Note: If you need to read the full text, please contact the publishing unit.A 10 mm quartz absorption cell with a 2% t content is filled with distilled water and a sodium iodide aqueous solution with a content of 10 g/L, respectively, and the reference and sample beams are placed. The transmittance T2 is measured, and the stray radiation rate TR is calculated according to formula (4): Tr = TiX T2
16.2 At 340 nm, 620 nm, and 1690 nm, a sodium nitrite aqueous solution with a content of 50 g/L, a 0.005% methylene blue aqueous solution, and dibromotoluene are used to detect each TI and T2 respectively according to the above method, and TR is calculated according to formula (4). * If the stray radiation rate of the instrument is greater than 0.1%, the attenuation plate should not be used. 17 Transmittance accuracy and transmittance repeatability 17.1 Ultraviolet region
The instrument bandwidth is 2nm. Use a set of standard quartz absorption cells to hold blank solution and ultraviolet spectrophotometry standard solution respectively. Measure the transmittance three times continuously at four wavelengths of 235nm, 257nm, 313nm and 350nm, compare with Table 1 in Appendix 3, and calculate the transmittance accuracy according to formula (5):4+:A=1-T,
Where: -- average value of transmittance measurement T -- standard value of transmittance.
Calculate the transmittance repeatability according to formula (6): 8: O, = Tmax-Tmin
Where: Tmax, Tmin
17.2 Visible region
Measure the maximum and minimum values of the transmittance three times (5)
The instrument bandwidth is 2nm, use a set of spectral neutral filters with transmittances of 10, 20, and 30%, and use air as a reference at wavelengths of 440nm, 546nm, and 635nm, respectively, and measure the transmittance three times in a row, compare it with the transmittance standard value of the neutral filter, and calculate △, and 5t according to formulas (5) and (6). When the instrument cannot be calibrated with a neutral filter, it is allowed to use ultraviolet and visible spectrophotometric standard solutions to calibrate the instrument transmittance.
18 Baseline straightness
Set the wavelength to the starting wavelength, take the normal scanning speed, bandwidth 2nm, range ± 0.01 (A) (or the most sensitive gear), the reference and sample beams are blank, and perform full-band or segmented scanning. Measure the difference between the starting point of each segment in the spectrum and the maximum offset, which is the baseline straightness*.
*Instantaneous jumps are allowed at the switching point of the light source and the detector. 19 Drift
After the instrument has been thermally balanced for 2 hours, set the wavelength to 500nm, take the bandwidth 2nm, normal scanning speed, range ± 0.01 (A) (the most sensitive gear), the reference and sample beams are blank, and the time scanning mode (or fixed wavelength scanning) is used. Scan for 0.5 hours and measure the change value of the parallel envelope line of the 0 (A) line on the spectrum. This is the drift of the instrument. 20 Noise
20.1100% Line Noise
Set the wavelength to 230nm (or 340nm), select time scan mode (or fixed wavelength scan), bandwidth 2nm, normal scan speed, range ± 0.01 (A) (most sensitive range block), reference beam and sample beam are both blank, time scan (or fixed wavelength scan), scan for 2min, measure the maximum peak-to-peak difference on the spectrum, which is the 100% line noise of the instrument. According to the above method, detect the noise at the wavelengths of 500nm and 1000nm respectively. 20.20% Line Noise
Take the range ± 0.1%T, put the light shield into the sample beam, and then detect the noise at the wavelength of 500nm according to the method of 20.1.
21 Insulation Resistance
Use a megohmmeter to check the resistance value between the instrument housing and the power supply line. Instruments in use can be exempted from inspection. 22 For other types of ultraviolet, visible, and near-infrared spectrophotometers that are not fully included in the scope of the provisions of this regulation, they can be calibrated in accordance with this regulation, and their technical requirements shall be based on the indicators in the instrument manual. V. Calibration result processing and calibration cycle
23 All the data of the above calibration shall be recorded on the record paper, and the spectrum and printed results shall be attached to the original record. 24 For instruments that pass the calibration, a calibration certificate shall be issued; for instruments that fail the calibration, a calibration result notice shall be issued, and the calibration results of the unqualified items shall be indicated.
25 The calibration cycle of ultraviolet, visible, and near-infrared spectrophotometers is one year. If the instrument is moved, repaired, or if the measurement results are found to be suspicious, it should be calibrated at any time. Note: If you need to read the full text, please contact the publishing unit.A 10 mm quartz absorption cell with a 2% t content is filled with distilled water and a sodium iodide aqueous solution with a content of 10 g/L, respectively, and the reference and sample beams are placed. The transmittance T2 is measured, and the stray radiation rate TR is calculated according to formula (4): Tr = TiX T2
16.2 At 340 nm, 620 nm, and 1690 nm, a sodium nitrite aqueous solution with a content of 50 g/L, a 0.005% methylene blue aqueous solution, and dibromotoluene are used to detect each TI and T2 respectively according to the above method, and TR is calculated according to formula (4). * If the stray radiation rate of the instrument is greater than 0.1%, the attenuation plate should not be used. 17 Transmittance accuracy and transmittance repeatability 17.1 Ultraviolet region
The instrument bandwidth is 2nm. Use a set of standard quartz absorption cells to hold blank solution and ultraviolet spectrophotometry standard solution respectively. Measure the transmittance three times continuously at four wavelengths of 235nm, 257nm, 313nm and 350nm, compare with Table 1 in Appendix 3, and calculate the transmittance accuracy according to formula (5):4+:A=1-T,
Where: -- average value of transmittance measurement T -- standard value of transmittance.
Calculate the transmittance repeatability according to formula (6): 8: O, = Tmax-Tmin
Where: Tmax, Tmin
17.2 Visible region
Measure the maximum and minimum values of the transmittance three times (5)
The instrument bandwidth is 2nm, use a set of spectral neutral filters with transmittances of 10, 20, and 30%, and use air as a reference at wavelengths of 440nm, 546nm, and 635nm, respectively, and measure the transmittance three times in a row, compare it with the transmittance standard value of the neutral filter, and calculate △, and 5t according to formulas (5) and (6). When the instrument cannot be calibrated with a neutral filter, it is allowed to use ultraviolet and visible spectrophotometric standard solutions to calibrate the instrument transmittance.
18 Baseline straightness
Set the wavelength to the starting wavelength, take the normal scanning speed, bandwidth 2nm, range ± 0.01 (A) (or the most sensitive gear), the reference and sample beams are blank, and perform full-band or segmented scanning. Measure the difference between the starting point of each segment in the spectrum and the maximum offset, which is the baseline straightness*.
*Instantaneous jumps are allowed at the switching point of the light source and the detector. 19 Drift
After the instrument has been thermally balanced for 2 hours, set the wavelength to 500nm, take the bandwidth 2nm, normal scanning speed, range ± 0.01 (A) (the most sensitive gear), the reference and sample beams are blank, and the time scanning mode (or fixed wavelength scanning) is used. Scan for 0.5 hours and measure the change value of the parallel envelope line of the 0 (A) line on the spectrum. This is the drift of the instrument. 20 Noise
20.1100% Line Noise
Set the wavelength to 230nm (or 340nm), select time scan mode (or fixed wavelength scan), bandwidth 2nm, normal scan speed, range ± 0.01 (A) (most sensitive range block), reference beam and sample beam are both blank, time scan (or fixed wavelength scan), scan for 2min, measure the maximum peak-to-peak difference on the spectrum, which is the 100% line noise of the instrument. According to the above method, detect the noise at the wavelengths of 500nm and 1000nm respectively. 20.20% Line Noise
Take the range ± 0.1%T, put the light shield into the sample beam, and then detect the noise at the wavelength of 500nm according to the method of 20.1.
21 Insulation Resistance
Use a megohmmeter to check the resistance value between the instrument housing and the power supply line. Instruments in use can be exempted from inspection. 22 For other types of ultraviolet, visible, and near-infrared spectrophotometers that are not fully included in the scope of the provisions of this regulation, they can be calibrated in accordance with this regulation, and their technical requirements shall be based on the indicators in the instrument manual. V. Calibration result processing and calibration cycle
23 All the data of the above calibration shall be recorded on the record paper, and the spectrum and printed results shall be attached to the original record. 24 For instruments that pass the calibration, a calibration certificate shall be issued; for instruments that fail the calibration, a calibration result notice shall be issued, and the calibration results of the unqualified items shall be indicated.
25 The calibration cycle of ultraviolet, visible, and near-infrared spectrophotometers is one year. If the instrument is moved, repaired, or if the measurement results are found to be suspicious, it should be calibrated at any time. Note: If you need to read the full text, please contact the publishing unit.
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