CNPA 200 200 Page 6 of 67 pages
/ Technical Specification for Type Approval of Illuminance Meters / S/N / CNPA 200Rev. / 1
1. This Technical Specification is enacted developed pursuant to Paragraph 3, Articles 25 of the Weights and Measures Act.
2. The date of promulgation, document numberNo., date of enforcement and content of the amendment are listed as follows:
Revision / Date of Promulgation / Document No.
(Ching-Piao-Szu-Tzu) / Date of Enforcement / Content of Amendment
1 / 18.06.2003 / No. 09240005630 / 01.07.2003
Date of Promulgation
18.06.2003 / Bureau of Standards, Metrology and Inspection, Ministry of Economic Affairs / Date of Enforcement
01.07.2003
1. Scope: ：This Specification shall be applied to the type approval of illuminance
meters having illumination below 1500 lx.
2. Construction:：
2.1 The measuring unit of illuminance meter is “Lux,” expressed by the symbol of“lx.”
2.2 The following items shall be indelibly marked on an easily visible position of each illuminance meter to avoid misrecognition:
(1) Class (AA, A or B);
(2) Type and serial number;
(3) Manufacturer’s name or trademark; and
(4) Measuring range of illuminance (if there are two and more measuring ranges, they shall be labeled separately).
2.3 The light-receiver can be spearated from illuminance meter in application. Both of the two parts shall be labeled by identical serial number and manufacturer’s name or trademark.
2.4 If the illuminance meter is equipped with a removable light attenuation filter, the same serial number shall be labeled on the illuminance meter and light attenuation filter and a protective cover shall be provided. Whenever the filter is taken off and put back again, the relative position of the two parts shall be maintained.
2.5 The displaying mechanism of the body of an illuminance meter shall be able to be adjusted and zero-setting.
2.6 The displaying mechanism of the body of an illuminance meter shall have a difference in illumination values, between horizontal position and any other position 30 degrees inclined from horizontal axis, that does not exceed the number of 2% of the maximum indicating scale in the measuring range.
2.7 The minimum scale intervals shall be no greater than 2% of the maximum indicating scale in the measuring range for analog illuminance meters, and no greater than 1% of the maximum indicating scale for digital illuminance meters.
2.8 If the illuminance meter is battery-powered, it shall indicate the rated voltage and display the state of insufficient power.
2.1 The measuring unit of illuminance meter is“Lux”and expressed by the symbol of “lx”.
2.2 The following items shall be indelibly marked on an easily visible position of each illuminance meter to avoid misrecognition：
(1) Class (AA, A or B)
(2)Type and serial number.
(3) Manufacturer’s name or trademark.
(4) Measuring range of illuminance (if there are two and more measuring range, label them out separately).
2.3 The light-receiver can be apart from illuminance meter in application, both of
the two parts should be labeled by identical serial number and manufacturer’s
name or trademark.
2.4 If the illuminance meter is equipped with a removable light attenuation filter, label
the illuminance meter and light attenuation filter in the same serial number and provide shelter cover to the filter. Whenever we take off the filter and put it on again, keep the relative position of the two parts fixed.
2.5 The displaying mechanism of illuminance meter body can be adjusted and reset.
2.6 The displaying mechanism of illuminance meter body should have an illumination difference between horizontal position and the other position 30 degrees inclined from horizontal axis that won’t be greater than 2% of the maximum indicating scale in the measuring range.
2.7 If the minimum scale intervals of illuminance meter for analog illuminance meter should be no greater than 2% of the maximum indicating scale in the measuring range, and no greater than 1% of the maximum indicating scale for digital iIlluminance meter.
2.8 If the illuminance meter is energized by battery, it shall indicate the rated voltage and display of insufficient power state.
3. Performance test
3.1 If the illuminance meter is energized by battery, when imposing voltage
deviation to the meter under effectively activated voltage range (to be emitted exposed to a light radiant strength equivalent to two thirds of the maximum measuring range), the deviation between the maximum and minimum displaying values should shall not be in excessexceed of 0.5% of the maximum displaying value. If the illuminance meter is energized by alternating current supply, when imposing voltage deviation to the meter under 10% rated voltage range (to be exposed to a light radiant strength equivalent to two thirds of the maximum measuring range), the deviation between the maximum and minimum displaying values shall not exceed 0.5% of the maximum displaying value.
If the illuminance meter is energized by alternating current supply, when imposing voltage deviation to the meter under 10% rated voltage range (to be emitted a light radiant strength equivalent to two thirds of the maximum measuring range), the deviation between the maximum and minimum displaying values should not be in excess of 0.5% of the maximum displaying value.
3.2 After the illuminance meter has been emitted exposed to a light radiant strength equivalent to two thirds of the maximum illumination value of the measuring range, the display value that degrades the illumination to zero by constant rate shall not exceed 1% of the maximum illumination value of the measuring range.
two thirds of the maximum illumination value of the measuring range, the display value that degrades the illumination to zero by constant rate should not be in excess of 1% of the maximum illumination value of the measuring range.
3.3 The illuminance meter that has been emitted exposed to a light radiant strength from zero to equivalent to one half of the maximum illumination value of the measuring range, should shall display the illumination value within 5 second.
3.4 When the light receiver has received and displayed the illumination equivalent to two thirds of the maximum illumination value of the tested range, the display values between 1 minute and ten minutes should shall not be greater than 1% of the 1-minute display value.
3.5 Put the illuminance meter at 0 oCºC, 10ºC oC, 23ºC oC, 30ºC oC and 40ºC oC separately.
After having getting achieved a heat- balanced state, the illuminance meter is emitted exposed to an illuminance equivalent to two thirds of the maximum illumination value of the measuring range for one minute; the display value (if there is a temperature compensation table is is attached, use the value after temperature compensation) deviated from the value at 23ºC oC should not exceed shall not exceed the value listed in Table 1.
Table 1
Class / Deviation of display valueAA / ±3% %
A / ±5% %
B / ±5% %
3.6 The difference of display values of the illuminance meter, at the condition of 23±±2ºC oC with, relative humidity between 45% and 75% (hereinafter referred to as the ““normal relative humidity””) and at the condition of the other one after return to normal relative humidity after having been exposed to an continuously staying under the ambient conditionatmosphere with that relative humidity is at 85%-95% (no condensate is formed) for three hours, then return back to the normal relative humidity, the deviation of display value should notshall not be greater than 3% of the former display value before the operation. Measurement of the display value shall be performed before and after the operation under the condition of normal relative humidity by having the illuminance meter exposed to an illuminance equivalent to two thirds of the maximum illumination within the measuring range value for one minute Before and after the illuminance meter put under the normal relative humidity, emit an illuminance equivalent to two thirds of the maximum illumination within the measuring range value for one minute to the illuminance meter and then perform the test.
3.7 Emit parallel light beam in the strength approaching to maximum scale to the base surface of light receiver. Rotate the base surface 30º, 60º and 80º relative to the two axes perpendicular to each other and count the test value by using the formula defined below. The calculated result shall not exceed the error defined in Table 2.
q = The rotated angle.
Eo = The indicated illumination when q is zero degree.
E = The indicated illumination after rotated q angle.
Table 2
Rotated angle / Class AAError / Class A
Error / Class B
Error
30º / ±2% / ±3% / ±3%
60º / ±7% / ±10% / ±10%
80º / ±25% / ±30% / ---
If the illuminance meter is equipped with a removable light attenuation filter, it shall comply with the values defined in Table 2.
3.8 Under the relative spectrum responding equipment, perform test for each 5 nm within the wavelength of 380nm-780nm and calculate the measuring values by using the formula defined below. The calculated results should not exceed the value defined in Table 3.
3.7 Emit parallel light beam in the strength approaching to maximum scale to the base surface of light receiver. Rotate the base surface 30-degree, 60-degree and 80-degree relative to the two axes perpendicular to each other and count the test value by using the formula defined below. The calculated result should not exceed the error defined in Table 2.
θ：The rotated angle.
Eｏ：The indicated illumination when q is zero degree.
E：The indicated illumination after rotated angle q.
Table 2
Rotated angle / Class AAError / Class A
Error / Class B
Error
300 / ±2 ﹪ / ±3 ﹪ / ±3 ﹪
600 / ±7 ﹪ / ±10 ﹪ / ±10 ﹪
800 / ±25 ﹪ / ±30 ﹪ / ----
If the illuminance meter is equipped with a removable light attenuation filter, it shall comply with the values defined in Table 2.
3.8 As corresponding to the relative spectrum responding equipment, perform test corresponding to relative spectrum responses for each 5 nm within the wavelength of 380nm-780nm and calculate the measuring values by using the formula defined below. The calculated results should not exceed the value defined in Table 3.
S*((λ): ) ：The normalized relative spectrum response after normalized according to the equation defined below.
I (λ): ：The spectrum strength of black radiation when the surface temperature
is 2856 K.
S(λ): ：The relative spectrum response of surface-receiver.
V(λ): ：The visual efficiency of spectrum.
Table 3
Class / Percentage of calculated valueAA / ±8 %
A / ±16 %
B / ±24 %
3.9 After the illuminance meter is exposed to ultraviolet zone, the value calculated from the following formula should shall not exceed ±1%.
EUV: ：The display value when a filter is attached for which mainly transmitsting only ultraviolet radiation.
EUV-R: ：The display value when a filter is attached for which both mainly transmitsting both to the ultraviolet radiation and the long wavelength.
E0 ：o: The display value in the circumstance of not putting any filter on the
illuminance meter.when no filter is attached.
The temperature distribution of light-emitting source is from 3000k to 3200k. Any filter allowing ultraviolet zone to go through will have the maximum spectral transmittance at a wavelength near 360 nm and which does not transmit a wavelength band fromof a 420 nm to 650nm. The cut-off wavelength of long wavelength in which a filter allows to go through is 620nm.
3.10 After the illuminance meter is exposed to ultrared zone, the value calculated from the following formula should shall not exceed the value defined in Table 4.
EIR: IR：The display value when a filter is attached for which mainly transmitsting only ultrared radiation.
E0o：: The display value in the circumstance of not putting any filter on the
illuminance meterwhen on filter is attached.
Table 4
Class / Percentage of calculated valueAA / ±1 %
A / ±2 %
B / ±5 %
The temperature distribution of light-emitting source is from 2846k to 2866k. The cut-off wavelength of ultrared radiation in which a filter allows to go through is 800nm.
3.11 The linear error of light receiver for digital illuminance meter should shall not exceed ±0.3%. The test procedure is illustrated below:
The value is measured first by having When the light receiver has received and displayed the illumination equivalent to the maximum illumination value of the measuring range, and measured again by having then the light receiver has received and displayed the 1/10 of the former illumination value of the measuring range again.
Calculate the linearity of light receiver from the following formulation:：
E1: The value when the light receiver has received and displayed the illumination equivalent to the maximum illumination value.
E0: The value when the light receiver has received and displayed the 1/10 of the former illumination valueequivalent to the maximum illumination valu.e
3.12 The digital illuminance meter circuit should shall carry a linear error no greater than ±1%. The test procedure is illustrated below:
When Expose the light receiver has receivedto the illumination equivalent to the maximum illumination value, and and measure the correspondedthe output current or voltage from it. Then expose the light receiver has receivedto the illumination equivalent to 1/3 and 2/3 of the equivalent to the maximum illumination value separatelyrespectively, and measure the corresponded output current or voltage from it again.
Calculate the linearity of illuminance meter circuit from the following formulations: