The machine is made up of three main parts: measuring circuit of electric parameter, measuring circuit of photometric parameter and circuit of CPU system. Voltage and current signals are amplify and sent to high speed A/D transform, and the transform digital signals are sent to microprocessor, the input current signals of brightness detector are sent to A/D transform via I/V convert, and the transform digital signals are sent to microprocessor. Microprocessor processing the input photometric and electric data, it automatic switch between different range and calculate and display the data in the mean time.

Technical characteristics:
? Simultaneous digital display in four windows, reduce the possibility of error reading
? Directly insert the tested lamp in the lamp holder is a quick and convenient means for use
? Measured electric values are true virtual value
? High correcting proficiency of photo detector V(λ), meet the brightness meter requirement of national Grade 1
? Wide test range, automatic switch between different range
? Double watchdogs inside make the instrument high reliability and won’t die at complicated environment

Characteristics and Specifications:
? Electric parameter:
    1. Measuring range: Voltage: 0-300V; Current: 0-0.5A/5A (Auto range switch)
    2. Input resistance: Voltage: greater than 1 MΩ; Current: less than 0.01Ω
    3. Frequency range: Base frequency 45Hz, band 5KHz
    4. Accuracy specification: Voltage, Current, Power: ±(0.4% read value+1digit)
    5. Power factor: ±(0.004+0.001/read value+1digit)
? Photometric parameter:
    1. Measuring range of brightness: 0.001kcd/m2-999.9kcd/m2
    2. Accuracy grade: 1 class
    3. Range: automatic switch between four grade of decuple scale