TENMARS ELECTRONICS TM-209N electrician tool

Purpose-built illuminometer

The TENMARS TM-209N is a handheld lux and foot-candle meter designed for electricians and lighting technicians who need to verify illumination levels on site. It measures intensity using a silicon photodiode with a filter that matches the CIE luminous spectral efficiency curve. The cosine-corrected sensor ensures accurate readings across a wide angle of incidence. The instrument complies with JISC 1609:1993 and CNS 5119 general A class specifications.

Spectral correction limits

The meter applies nine factory correction factors so that readings reflect the true output of different light sources. Standard source A and LED white daylight are referenced at 1.00 and 0.990 respectively. Neon colours deviate more strongly: blue at 1.286, green at 1.167, pink at 0.760, purple at 0.804, red at 0.671, yellow at 0.840 and white at 0.870. Users working with unlisted spectra or requiring laboratory-grade uncertainty will need a spectroradiometer instead.

Field-ready construction

The red enclosure houses the sensor, display and controls in a single handheld unit powered by user-supplied batteries. A data-hold button freezes the reading for notation and the memory stores up to 99 manual records for later review. The package includes only the meter; batteries are not supplied. Buyers who need continuous logging, PC connectivity or a carrying case should look for a model that provides those features.