Verification Regulation of Ultraviolet, Visible, Near-Infrared Spectrophotometers
1 Scope
This regulation is applicable to the first verification, subsequent verification and in-service inspection of visible, ultraviolet-visible and ultraviolet-visible-near infrared spectrophotometers with continuously adjustable wavelength ranging from 190 nm ~ 2600 nm.
2 Normative references
The following documents are referenced in this regulation:
OIML R135 International recommendation OIML R135 Edition 2004 Spectrophotometers for medical laboratories
JJF 1001-1998 General Terms in Metrology and Their Definitions
JJF 1059-1999 Evaluation and Expression of Uncertainty in Measurement
While applying this regulation, attention shall be paid to make sure that the referenced ones are currently effective editions of the above documents.
3 General
Ultraviolet-visible-near infrared spectrophotometer (hereinafter referred to as the instrument) is an instrument for quantitative analysis and qualitative identification of substances according to the selective absorption of ultraviolet, visible and near infrared radiation (light) by molecules of substances and Lambert-Beer’s law.
The mathematical expression of Lambert-Beer's law is:
A = -lg(I/Io) = -lg T = klc
where,
A — the absorbance of substance;
Io — the intensity of incident monochromatic light;
I — the intensity of transmitted monochromatic light;
T — the transmittance of substance;
k — the absorption coefficient of substance;
l — the optical path of the substance to be analyzed;
1 Scope
2 Normative references
3 General
4 Measurement performance requirements
4.1 Maximum permissible error of wavelength
4.2 Wavelength repeatability
4.3 Noise and drift
4.4 Minimum spectral bandwidth
4.5 Maximum permissible error of transmittance
4.6 Transmittance repeatability
4.7 Baseline straightness
4.8 Power supply voltage adaptability
4.9 Stray light
4.10 Matching of the absorption cell
5 General technical requirements
5.1 Safety performance
5.2 Marking
5.3 Appearance
5.4 Absorption cell
6 Control of metrological instruments
6.1 Verification conditions
6.2 Verification items
6.3 Verification method
6.4 Treatment of verification results
6.5 Verification period
Annex A Reference wavelength of wavelength reference materials
Annex B Transmittance of potassium dichromate standard solutions at the corresponding wavelengths with different temperatures and spectral bandwidths
Annex C Preparation method of standard solution
Annex D Inside page format of verification certificate
Annex E Recording format of ultraviolet, visible, near-infrared spectrophotometers verification
