Konica Minolta T-10A - Cosine Correction Characteristics; JIS Cosine Correction Analysis

52
[Conforms to JIS]
Ideally, the relative spectral responsivity of the illuminance meter should match V (λ)
the spectral luminous efficiency of the human eye for photopic vision.
As shown in the graph above, the relative spectral responsivity of Konica Minolta Illuminance
Meters T-10A/T-10MA is within 6% (f1’) of the JIS spectral luminous efficiency V (λ).
Class General class Precise General class AA General class A
f
1’ (%) 3 6 9
JIS ; Japanese Industrial Standards
f’1 (JIS’s symbol) ; The degree to which the relative spectral responsivity matches
V (λ) is characterized by means of the error f
1’.
Note : The contant has the dimension nm
-1
S’(λ)
rel
normalized relative spectral responsivity
P(λ)
A
Spectral distribution of the illuminant used in the calibration
(standard illuminant A)
S(λ)
rel
Relative spectral responsivity with arbitrary reference
V(λ) Spectral luminous efficiency of the human eye for photopic vision
d λ Wavelength pitch
λ
1
Lower limit of visible wavelength region
λ
2
Upper limit of visible wavelength region
S ( )rel =
P(λ)AV(λ) dλ
P(λ)AS(λ)rel dλ

• S(λ)rel
λ
λ1
λ
2
ʃ
λ1
λ2
ʃ
′
0
10
20
30
40
50
60
70
80
90
100
Relative spectral response (%)
750700650600550500450400
Wavelength (nm)
The spectral luminous efficiency
Konica Minolta Illuminance Meters T-10A/T-10MA
f1′ =
λ1
λ
2
S′(λ)rel -V(λ) dλ
V(λ) dλ
×100(%)
ʃ
λ1
λ2
ʃ
Relative Spectral Response