The Yokogawa 510 Series digital illuminance meter is available in 2 models. The Yokogawa 510 01 conforms to
standard general class A of JIS C 1609-1993 "Illumination Meter". The Yokogawa 510 02 conforms to standard
general class AA of JIS C 1609-1993 "Illumination Meter". In the new JIS standard, the system of evaluating
the characteristics of the visible region relative spectral response is changed in order to bring the relative
spectral response of the illuminance meter closer to the unit of brightness human beings are considered
sensitive to.
The Yokogawa 510 Series digital illuminance meter features 3 output types: recorder output, digital output,
and comparator output. The timer hold function is added to the Yokogawa 510 Series digital illuminance meter
so that the shadow of the user or reflections from clothes do not affect the measuring intensity of
illumination. Like an automatic camera shutter, a measured value is held five seconds after the switch has
been pressed.
The Yokogawa 510 Series digital illuminance meter measures the intensity of illumination more accurately
because its sensitivity approximates to the standard spectral luminous efficiency (conforming to the new JIS
standard) which is the same sensitivity as the human eye. However, since spectral characteristics differ
depending on the light source types, a subtle indication error occurs.