Light Meter

It is bright but how bright is it? What’s the colour of light? Both of these questions come up again and again now that conventional lamps are more and more replaced by LEDs. A light meter can help answer these questions precisely. All light meters from PCE Instruments’ range of products measure the brightness of light sources. These meters for light meters have different sensors and some have additional light measurement functions.

The standard light meter is equipped with a photocell for analogue capturing of the light value which will then be shown in the display as the brightness value. To make sure the light incidence on the light meter’s photocell is even, the sensor is located behind a diffused dome. All these light meters work in line with the CIE standard. They can measure the brightness of any visible light source. This means that any light meter can measure conventional lamps as well as LED lamps, except blue light or blue Led light which cannot be measured due to the wavelength of the light.

Light meters with additional measuring functions such as measurement of the colour temperature or the colour of light require a different type of sensor. An array of modern CCD sensors measures the brightness, the wavelength, etc. of the light. These sensors in the light meter are similar to a photosensor in a digital camera. These modern spectrometers can measure the exact composition of light and display them as a measurement value. Light meters with a spectrophotometer function or with a CCD pixel sensor can measure all types of light, even blue LED light.

Light meters can also have different accuracies and are based on different measurement standards. A typical light meter will have accuracy class B. In numbers, this is an accuracy of ±8 % of the light reading. Most light meter models from PCE Instruments offer an accuracy of ±8 % from the reading- which is between accuracy class A and B for a light meter.

Many of these light meter models are equipped with an interface that allows the user to transfer the data of a series of measurement to a PC. Moreover, some light meters have an internal memory to save the measurement values.

Various measuring attachments which are optionally available or included in the standard package of the light meter enable the user to measure the luminance of monitors or other light sources.

Most light meters are available with an optional calibration certificate. However, please bear in mind that the cost of calibration is relatively high and that a calibration of a cheapish light meter often does not make much sense.

If you require individual support on our light meters, please do not hesitate to contact our technical support.

Lighting and illumination have become essential in any sphere of life and they perform an auxiliary function when daylight is not enough or is absent. How much light is necessary? Is artificial light necessary if a natural light, both, inside and outside, is available? When is artificial light a huge help and when is it a complete waste?

A light meter is a device that helps to answer all these and other questions. It is a device which finds its application literally everywhere, from household to work places, streets, recreational and other facilities, illumination of the highspeed and other roads, all possible types of establishments and institutions. A very sensitive electrical device helps to monitor and control the level of illumination of any area. Lux is a standard, well-known unit, in which the measurements are expressed. Another possible term used in some systems may be foot candle (lumens per square foot).

Light meter is small in size, convenient to operate and since modern devices are equipped with a lighted screen (made of special glass), the reading of the measurements is significantly facilitated. Robust housing of the device protects the photocells from possible damages and excessive exposure to direct light of different origin (it may be natural sunlight, fluorescent light, high-intensity discharge lights, based on different gases).

The majority of people spend a big part of their day at work and it is natural that certain conditions should be created, so that the health and well-being of the workers was not damaged while they are performing their professional tasks. The quality of work and performance directly depends on how comfortable and safe the worker feels at the work place. Depending on the occupation, the amount of required light may differ tremendously. So, excessive light is as bad as scarce and this is quite a challenging task to create perfect working conditions for each particular task.

Besides, “comfort level” factor, which matters in general for any person, there is also “performance” factor. They now always coincide, due to a huge variety of jobs and tasks, but they should be kept in a certain balance. Educational establishments, hospitals, laboratories, factories etc. – these are the places where the level of light should be sufficient for 100% productivity. For example, if the light required is too bright or it should be too dim, the working process should be organized in such a way, so that the worker had enough breaks, allowing the eyes to relax, and was wearing respective eye protection. At the same time, it should not cause problems for the workers fulfilling other tasks, and whose comfort is totally disturbed by the improper lighting.

Arranging proper illumination for the workers performing their tasks outside is even more complicated, since it is difficult to predict and count on permanent stable illumination by natural light sources. That is why auxiliary lighting sources must be provided if the level of the natural light is not sufficient. The same relates to the professionals working in the dark time of the day or having late shifts. The range of workplaces and illumination requirements to them is extremely wide, but all of them have been classified and organized by the official authorities. Health care organizations pay a big attention to this issue, and numerous rules, standards and regulations are continuously discussed and monitored. The requirements to lighting at workplace may be found in the guidelines of International commission on Illumination, ISO 8995, Society of Light and Lighting (SLL) in Britain, European Norms, Illuminating Engineering Society of North America (IES) and similar organizations.

Humanity has developed a variety of man-made light sources to illuminate the dark and to light indoor spaces. Recommendations for indoor lighting depend on consumer preference and the location of the light source (e.g., home, office, school, parking lot, street, theater or hospital examination room, operating room, recovery room, etc.).

One of the most popular achievements in modern lighting technology is the light emitting diode (LED). LED lights can be found almost anywhere, inside and outside, and are available in different sizes and colors. The LED's greatest advantages are low energy consumption and long service life. These attributes make LEDs very attractive to consumers. LEDs do not emit as much heat as incandescent lights. Even when an LED light is on, there is no risk of burning the skin if the light bulb is touched. In addition, thanks to their epoxy lenses, LEDs are not too fragile. Though LEDs are quite popular nowadays, other types of indoor lighting still are widely used.

The aforementioned incandescent light has been used for decades in numerous indoor lighting applications. Incandescent light bulbs produce a soft and pleasant glow. This is why incandescent lighting still can be found in residential homes, even though incandescent light bulbs consume much more energy. Incandescent lamps get warm over time, and though the extra heat can help keep indoor temperatures warmer during the winter months, careful handling of recently or currently illuminated bulbs is required, because touching the hot light bulbs can burn the skin.

Another alternative to incandescent lighting is halogen lighting. Sometimes halogen light bulbs are selected for use in table lamps, inside and under cabinets, and in different wall-mounted fixtures. Halogen lights are small in size, contain halogen and inert gas, and offer a higher level of brightness and a longer service life.

Integrated compact fluorescent light (CFL) bulbs are reminiscent of incandescent light bulbs, because both kinds of bulbs feature the same base. Integrated CFLs can be used in many standard incandescent light fixtures. The difference between integrated CFL and incandescent light bulbs is that the service life is much longer (in average 8 – 13 hours) and the energy consumption is ¾ lower for integrated CFL bulbs. Aesthetically, the twisted-tube design of the integrated CFL bulbs looks much different than the egg-shaped design of the incandescent light bulbs. For this reason, some consumers prefer to use incandescent light bulbs in clear glass light fixtures.

Traditionally, when one thinks of fluorescent lighting, one envisions the long tube-shaped bulbs frequently used in industrial-looking overhead light fixtures. Since these large fluorescent bulbs produce a very bright light, they are often referred to as daylight lamps. Because there is a certain amount of mercury in these kinds of light bulbs, the bulbs should be handled and disposed of carefully.

Lastly, neon lighting can be found in some indoor environments. Neon lighting is comprised of electrified glass tubes filled with rarefied neon or other gases. The type of gas used in the tube determines the color of the neon light. Neon lights can be used for decorative lighting in bars and nightclubs as well as for small indicator lights in electronic displays.

Therefore, indoor light bulb selection largely depends upon the intended application. However, whether a light bulb is needed for ambient lighting, spotlighting or task-specific use, factors such as service life, energy consumption, aesthetics and price are almost always considered. In addition, special functions like dimming often are added to the equation. Only after analyzing all the required (and desired) lighting parameters can the best (most suitable) indoor lighting solution be identified.

A standard light meter is a useful tool for evaluating indoor lighting conditions, especially those involving incandescent and fluorescent light bulbs. When evaluating LED lighting indoors, an LED-specific light meter is recommended.

Should you have any questions about light measurement using a light meter, please do not hesitate to contact the PCE technical sales and support team at  or +44 (0) 2380 987 035 for PCE Instruments UK, or at  or +1 (561) 320-9162 for PCE Americas Inc.