LM-100 Light Meter

The Amprobe LM-100 light meter measures the visible light from fluorescent, metal halide, high-pressure sodium or incandescent sources. It is a portable, easy-to-use digital light meter designed for simple one-hand operation reading in Lumen (lux) or Footcandle (fc) units. The LM-100 measures a wide range of light up to 20,000 fc or lux with an accurate, high resolution of 0.01 fc/lux.

Use the LM-100 light meter to measure the illuminance level in the interior and to switch off or reduce or increase the output level of lighting fixtures. Reduce the energy burdenof the building by significantly increasing the efficiency of itslighting system.

One lux is the illumination from a one candlea lamp perpendicular to a surface one meter squared at a distance of one meter. One fc is the illumination from a one candela lamp perpendicular to a surface one foot squared at a distance of one foot. 1 footcandle = 10.764 lux and 1 lux = 0.09290 footcandles.

LM-100 Light Meter Features

  • Measure in Lux or Footcandles, front panel switchable
  • Measuring range to 200000 Lux or 20000 Footcandles
  • Silicon photodiode sensor and filter
  • Data Hold to freeze reading on the digital display
  • MAX ability to show high readings
  • Includes protective sensor cap
  • Large, 3-1/2 digital display


Illumination Accuracy at 23° C ± 5° C (73.5° F ± 5° F), < 75% R.H.
Sensor Silicon photodiode and filter
Measurement rate 2.5 times per second
Range 20, 200, 2000, 20000, 200000 Lux20, 200, 2000, 20000 Footcandles
Accuracy ± 3% (Calibrated to standard incandescent lamp at 2854°K)6% other visible light sourcesAngle deviation from cosine Characteristics30° ±2%60° ±6%80° ±25%

Cosine Angular corrected per JIS C 1609:1993 and CNS 5119 general A class

Resolution 0.01 fc/lux
General Specifications
Display 3¾digit liquid crystal display (LCD) with a maximum reading of 1999
Sampling Rate 2.5 times per second for digital display
Polarity Automatic, positive implied, negative polarity indication
Overrange (OL) or (-OL) is displayed
Zero Automatic
Low battery indication The Battery symbol is displayed when the battery voltage drops below the operating level
Temperature/Humidity Operating -10°C to 50°C (14°F to 122°F), 0 to 80%RHStorage -10°C to 50°C (14°F to 122°F), 0 to 70%RH
Altitude 2000m, indoor operation
Power Supply 9V NEDA 1604, IEC 6F22, JIS 006P battery
Battery life 200 hours
Auto Power Off Approx 6 min
Dimension (Base) 130 x 63 x 38mm (5.1 x 2.5 x 1.5”)
Dimension (Sensor) 80 x 5 5x 29mm (3.2 x 2.2 x 1.1”)
Weight 220 g (.48 lb.) include battery
Agency Approvals & Certifications