Excellent characteristics in Visible region relative spectral response. In the JIS standard, the system of evaluating the characteristics of the visible region relative spectral response is adopted in order to bring the relative spectral response of the lux meter much closer to this ideal.
Color correction factor setting function:
The 510 series lux meter measures the intensity of illumination more accurately because its sensitivity approximates to the standard spectral luminous efficiency 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. The 51021 lux meter incorporates a function to correct this error. (Factor fixed: 8 types; arbitrary factor setting: 21 types)
Timer hold function:
This function is added so that the shadow of the user or reflections from clothes do not affect the measuring intensity of illumination. Like an selftimer function of a camera, a measured value is held five seconds after the switch has been pressed. The 51021 lux meter can be set arbitrarily from 1 to 999 seconds.
Light source luminous intensity measurement function:
The luminous intensity (candela) can be measured easily by setting the distance from the light source (0.01 to 99.99m).
Average illuminance computation function (correspondence to 4-point and 5-point methods):
This function automatically calculates 4 or 5 points average of illumination. JIS C 7612 [Illuminance Measurements for Lighting Installations] describes how to calculate the average illuminance using the 4-point and 5-point methods.
USB function (Power supply and communication): With the USB interface, it can be used as a power supply source for continuous measuring with recorder output or/and USB communication.