Illuminance Meter Technical Parameters Introduction and Selection Guide
An illuminance meter is an instrument that specializes in measuring luminosity and brightness. It is to measure the light intensity (illuminance) is the degree to which the object is illuminated, that is, the ratio of the luminous flux obtained on the surface of the object to the illuminated area. An illuminance meter is usually composed of a selenium photocell or a silicon photocell and a microammeter.
Calibration principle:
Let Ls vertically irradiate the photocell → E=I/r2, change r to get the photocurrent value under different illuminance, and convert the current scale into the illuminance scale by the corresponding relationship between E and i.
Calibration method:
Using the light intensity standard lamp, under the working distance of the approximate point light source, change the distance l between the photocell and the standard lamp, record the readings of the ammeter at each distance, and calculate the illuminance E by the inverse square law of distance E=I/r2, and then calculate the illuminance E by This can get a series of photocurrent values i with different illuminance, and make the change curve of photocurrent i and illuminance E, which is the calibration curve of the illuminance meter. From this, the calibration of the illuminance meter can be done by dividing the dial of the illuminance meter.
Factors affecting the calibration curve:
The photocell and galvanometer need to be re-calibrated when they are replaced; the illuminance meter should be re-calibrated after a period of use (generally 1-2 times within a year); the high-precision illuminance meter can be calibrated with a light intensity standard lamp; The calibration range of the illuminance meter can change the distance r, or choose different standard lamps, and choose a small-range galvanometer
Scope of application:
1. General public places
In order to ensure that people can live under suitable light, my country has formulated health standards for indoor (including public places) illuminance, and used illuminance meters to measure the illuminance of various places.
2. Lighting production industry, photography industry, stage lighting layout, etc.
The illuminance meter has been successfully applied to many projects, such as lighting production industry, photography industry, stage lighting layout, etc. Different models of illuminance meters can meet different measurement requirements.
3. Factory production line
In the factory, the illumination requirements on the production line are relatively strict. Continuous work will cause visual fatigue and greatly reduce work efficiency. Usually, the illumination requirement is ≥1000Lx. For places with relatively high illumination requirements, a large-range illuminance meter can be selected, with a super-large range. , can deal with strong light illuminance measurement.
4. The application of illuminance meters is very extensive, including the applications in our daily life, such as factories, warehouses, schools, offices, homes, street lighting construction, laboratories and so on.
How to choose a suitable illuminance meter
The illuminance meter is a special instrument for measuring luminosity and brightness. The illuminance is closely related to people's life. Sufficient light can prevent people from accidents. Conversely, too dark light can cause human fatigue far more than the eyes themselves. Uncomfortable or poor lighting conditions are therefore one of the leading causes of accidents and fatigue.
There are many models of illuminance meters on the market, and users are often at a loss when purchasing, and do not know which model is suitable for their own use. How to choose a light meter? In fact, as long as you choose products from regular manufacturers, there is no problem. Generally, pay attention to the following points:
1. It must be convenient to carry, because there are many opportunities to use the illuminance meter, and the timing of use is often in different places, so a portable illuminance meter with small size and light weight can maximize work efficiency.
2. The accuracy is high, so that you can give yourself professional data reference.
3. For measurement range and high-illuminance measurement, choose a large-range illuminance meter. Generally, the large-range range on the market can detect 400,000 Lux to meet the needs of high-illuminance detection. For low-light measurement, such as darkroom illuminance detection, it is necessary to choose a low-light illuminance meter, which can detect a minimum of 0.0001lux.
4. The illuminance meter is an instrument with very sensitive photosensitive elements. Therefore, if the user unit needs to issue a measurement verification certificate, it is best to choose a regular manufacturer to produce products, which can minimize the occurrence of unqualified inspections.
