Testo 540 Pocket Lux Meter (Light Intensity Meter) – 0…99,999 Lux, Hold and Max./Min., Illuminated Display (0560 0540)

Testo 540 (product code 0560 0540) is a pocket lux meter (light intensity meter) that measures the illuminance of artificial and natural light. It has a measuring range of 0 … 99,999 lux; since its light sensor is matched to the spectral sensitivity of the human eye, it is suitable for quick spot checks of lighting conditions in workplaces, shops and offices.

Quick Check of Lighting Levels in the Workplace

The instrument takes a measurement every half second and shows the value on a large, illuminated display. The Hold function keeps the last value on the display; max. and min. values can be displayed and reset with a single button. The measuring unit can be selected as lux or foot candle (ftc). The protective cap keeps the sensor safe when the instrument is not in use.

Its small body fits in a pocket; with 2 × AAA batteries it runs for an average of 200 hours with the display illumination off. Auto-off (10 minutes) can be switched on and off in the settings menu.

Technical Specifications (Official Testo Information)

• Brand / Model: Testo 540 lux meter · product code 0560 0540
• Sensor: silicon photodiode, matched to the spectral sensitivity of the eye
• Measuring Range: 0 … 99,999 lux · 0 … 9,300 ftc
• Accuracy: ±3 lux or ±3% of measured value (relative to DIN 5032 Part 7 class B reference, whichever is greater)
• Resolution: 1 lux (0 … 19,999 lux), 10 lux (remaining range)
• Measuring Rate: 0.5 s
• Functions: Hold, max./min., illuminated display, lux / ftc unit selection, auto-off after 10 minutes (can be disabled)
• Power Supply: 2 × AAA batteries · battery life on average 200 hours (with display illumination off)
• Operating / Storage Temperature: 0 … +50 °C / −40 … +70 °C
• Protection Class: IP40
• Dimensions / Weight: 133 × 46 × 25 mm · 95 g (including battery and protective cap)

Scope of Delivery

• Testo 540 lux meter
• Protective cap
• Test protocol
• Batteries

Technician Recommendations

• Hold the instrument horizontally: for accurate measurement, hold the instrument in a horizontal position with the light sensor facing upward.
• Keep the measuring height constant: measure at the level of the working surface, such as a desk, counter or floor; take comparative measurements at the same height.
• Do not cast shadows: do not cast a shadow over the sensor with your body or hand during measurement.
• Measure at several points: the illuminance varies within an area; take measurements at different points in the room and evaluate the lowest and average values.
• Protect the sensor: fit the protective cap after measuring; wipe a dirty housing with a damp cloth and do not use solvents.

Technical document: Testo 540 lux meter product brochure (PDF, Turkish)