Steps in the use of illuminance meter and illuminance calibration
Steps for use
① Turn on the power.
② Open the light detector cover and place the light detector horizontally in the measurement position.
③Select the appropriate measuring position.
If only "1" is shown on the left end of the display, it means that the illuminance is too much and you need to press the range key (⑧ key) to adjust the measurement multiplier.
④ The illuminance meter starts working and shows the illuminance value on the display.
⑤ The data shown on the display changes constantly, when the display data is more stable, press the HOLD key to lock the data.
⑥ Read and record the observed value shown in the readout. The observed value is equal to the product of the number displayed in the readout and the range value.
For example: 500 is displayed on the screen, the lower right corner of the display status is "×2000", the illuminance measurement value is 1,000,000lx, i.e. (500 × 2000).
⑦ Press the lock switch again to cancel the reading value lock function.
⑧ Each observation, three consecutive readings and record.
⑨ After each measurement is completed, press the power switch button to cut off the power supply.
⑩Cover the lid of the light detector and put it back in the box.
Illumination calibration
Principle of calibration:
Make Ls irradiate the photocell vertically → E=I/r2, change r to get the value of light current under different illuminance, and convert the current scale to illuminance scale by the correspondence between E and i.
Calibration method:
The use of light intensity standard lamp, in close proximity to the working distance of the point light source, change the photocell and the standard lamp distance l, recorded under the distance of the ammeter readings, by the inverse square law of distance E = I / r2 calculation of light illuminance E, which can be obtained from a series of different illuminance of the light current value of i, for the photocurrent i and the illuminance of E curve, that is, for the illuminance of the calibration curve from this illuminance can be made to dial Indexing that is the calibration of the illuminance meter
Factors affecting the calibration curve:
Photocells and ammeter replacement needs to be re-calibrated; illuminance meter should be used for a period of time should be re-calibrated illuminance meter (generally should be checked 1-2 times a year); high-precision illuminance meter can be used to check the light intensity of the standard lamp; expanding the range of illuminance meter can be changed to the distance r, you can also choose a different standard lamp, the use of small range of ammeter
