Testing based on the "Design Specification for Ventilation and Lighting of Highway Tunnels" JTJ026 · 1-1999 "Design Specification for Highway Tunnels" JTG D70-2004

3. Detection Method

  3.1 As needed, turn on the light source to be tested and eliminate the influence of other unrelated light sources

  When measuring, the illuminometer first uses a large range of gears, and then gradually finds the appropriate gear based on the indicated value. In principle, it is not allowed to read the indicated value within 1/10 of the maximum range

  3.3 After the illumination reading is stable, read it again. The last digit reading of a digital illuminometer is sometimes unstable, and the number with the most occurrences should be recorded. 3.4 In order to improve the accuracy of measurement, 2-3 readings are taken at each measuring point, and then the average value is taken&Nbsp

  4. On site records 4.1 The measurement results should be recorded in a pre prepared table 4.2 Measurement Record Content (1) Measurement Date, Time, Climatic Conditions, and Name of Measurement Personnel; (2) Measurement location; (3) Model and specifications of light sources and fixtures; (4) Installation method, spacing, height, etc. of lighting fixtures; (5) On site measurement conditions (environmental conditions, power supply conditions); (6) The usage time of light sources and fixtures, and the last cleaning time; (7) Layout of illumination measurement points with dimensions marked; (8) Illumination measurement values at each measuring point; (9) Average illumination and calculation results of average illumination; (10) Illuminometer model, number, and identification date&Nbsp 5. Calculation of average illumination and uniformity; 5.1 Average Illuminance The average value of all measuring points in the measuring area is the average illuminance of the area; 5.2 Uniformity The ratio of the minimum illuminance in this testing area to the average illuminance in this area is extremely high. The total uniformity of the illuminance in this testing area U0=Lmin/Lev The ratio of the minimum brightness in this testing area to the average brightness in this area is extremely high. The longitudinal uniformity of the road surface brightness in this area U1=Lmin/Lmax The ratio of the minimum brightness in the centerline to the maximum brightness in the centerline is 5.3 The conversion of brightness to illuminance L=E/C: Illuminance C: Concrete pavement C=13, asphalt pavement C=22

; 6. Precautions 6.1 For tunnels less than 200m, there is no intermediate lighting section 6.2. When measuring, the light output of the light source should be stable before measurement. Therefore, before starting the measurement, the filament lamp should be turned on 5 minutes in advance; Fluorescent lamps need to be turned on 15 minutes in advance; The high-strength gas discharge lamp should be turned on 30 minutes in advance; For newly installed lighting systems, measurements are also taken after 100 hours of ignition for fluorescent lamps and 10 hours of ignition for incandescent lamps. 6.3 Measurement personnel should wear dark clothing to prevent the influence of the figures of measurement personnel and onlookers on the receiver. When measuring, it is advisable to keep the power supply voltage stable and maintain the measurement at the rated voltage. If it cannot be done, the power supply voltage should be measured. When it does not match the rated voltage, the luminous flux should be corrected according to the voltage deviation