Extech LT45

The LT45 is built for LED lighting, which is what most SAD lamps and home bulbs now use. Its ±3% basic accuracy is among the tightest specs here, and unlike the budget meters that claim similar figures, its datasheet confirms cosine and color correction.

The more useful evidence is independent. In a 2018 Budget Light Forum comparison against a MobiLux Class A meter, the LT45 read 1.7% to 7% high across six LED sources. The tester summarized it as a 4.5% average calibration offset with 1.35% spread across sources, and noted that its spectral response closely matched the reference.

A consistent offset is easy to live with: the meter reads slightly high, by about the same amount, whatever the LED. Budget meters in the same tests swung by much larger and less predictable amounts between LEDs.

The LED-type setting (white, red, yellow, green, blue) is aimed at colored LEDs. For checking a white SAD lamp or ceiling lights, leave it on white.

The sensor sits on a coiled cable that extends to 1.5 m, which helps when you want the sensor at eye height in front of a lamp while you stand back to read it. It also stores 99 readings, useful for mapping light across a room.

Extech’s product page lists two AAA batteries, while its datasheet and product text mention a 9V battery. Check the box before buying spares.

Choose the LT45 over the Extech LT300 if you mostly measure LEDs and want the tighter spec and test data. Like any lux meter, it cannot show melanopic light; for that you need a spectrometer such as the UPRtek MK350S Premium.