A lux meter (sometimes called a light meter or an illuminance meter) is a handy tool for measuring the amount of light in an area or on a surface.
You can use them to get the right amount of light for growing plants, or to display artwork in controlled conditions. You can even just use one to get the best ambiance at home.
But does a regular lux meter work with LED lighting, or do you need a special one for LED lights?
A standard lux meter won’t work accurately with LED lighting. The light sensor can only detect white light, while LEDs produce light with a higher blue wavelength. Special lux meter for LED lights is required to measure LEDs or certain colors of light, including purple, blue, or red lights.
In this guide, I’ll explain to you:
- What a light meter actually measures
- The differences between regular light meters and LED light meters
- How to use an LED light meter to check the brightness of LED light sources
What Does A Lux Meter Measure?
A lux meter is used for measuring lumens on any particular surface in lux – lumens per square meter. Most light meters will also let you work in foot candles, which is lumens per square foot if you prefer to work in English units.
They consist of a handheld unit with a sensor either built-in, or attached via a cable. This sensor should be placed on the surface where you want to check the brightness, and it’ll detect the light intensity at that level.
It’s great if you want to check the lux level of a room or of a particular area – such as checking whether your new lighting installation is suitable for a kitchen worktop or if you need extra light fixtures/brighter bulbs to keep it safe.
They’re also used in a lot of professional settings, checking street lights are safe, for example.
If you’re a keen gardener, then you’ll probably want a PAR meter instead. They’re more expensive, but they specifically measure the wavelength of light needed for plants to photosynthesize.
LED Light Meter Vs Regular Light Meter: What Is The Difference?
Regular light meters are designed to capture white light only, while an LED light meter specifically measures the wavelengths of light from an LED light source. If you’re installing LEDs in your home, you need the right light meter to check the lux accurately.
It’s because of the wavelengths of light used by LEDs, which are more in the blue spectrum. Regular light meters are trying to detect different energy wavelengths and so won’t read the brightness of a room correctly.
It’s even worse if you’re using red or blue LED lights, or a purple light. A regular light sensor has no chance at measuring these lights accurately! Whereas the color correction filter on an LED light meter will always give an accurate reading.
The good news is that an LED light meter can do the job of a regular one, too.
So you’ll likely find that more of these instruments are capable of measuring the brightness of LEDs along with older lights, such as fluorescent, incandescent, or high pressure sodium light sources.
Light Meter Vs Lux Meter
There’s no difference between a light meter and a lux meter – they’re different names for the same device. They can sometimes be called illuminance meters, though this is less common.
If you’re shopping for an LED light meter, and you find an LED lux meter, that’s the right thing to buy. Just make sure it is suitable for LEDs.
How To Measure LED Light Intensity With Lux Meter
While every LED light meter is unique, they typically have similar features. To use them:
- Hold down the power button on the light meter until it switches on
- Place the sensor on the surface that you want to check
- Wait for the display to settle on a reading
A lot of light meters will let you use a ‘Data Hold’ button to store the number on the screen. So you can press it, and then move the device without losing the reading.
Others will also have the option to review prior readings, including minimum and maximum readings. If you’re using LED light meters to check the brightness of a specific area, this can be really useful for comparing the different light levels without making manual notes.
- Measures light intensity from white LED light sources up to 40k Foot candles (400k Lux) as well as...
- Silicon photodiode sensor and filter
Last update on 2024-02-22 / Affiliate links / Images from Amazon Product Advertising API
Other features to look out for on these kinds of devices are a hard carrying case, if you’re a professional who needs to carry it around with you, and a rotatable sensor that lets you easily check light in multiple directions.
There are some phone apps that claim to let you measure light, but they’re not as effective as proper lux meters.
A lux meter can be a handy tool, but buying the correct model is important. Make sure you get an LED model if you’re measuring LED lights – and in the future, you probably will be.
Yes, they are more expensive than the sensors that plug into your phone, but it’s better to choose accuracy with proper light meters – and you can still get one for a great price.
But remember that a PAR meter will be more useful if you want to grow plants – and I’ve got a guide on using LED strips for growing plants too, which is worth checking out.