YOKOGAWA 51021 Digital Light Meter

YOKOGAWA 51021 Digital Light Meter exhibits excellent characteristics in the visible region relative spectral response. It is a wide range, high accuracy meter with five ranges of 0.0 to 99/ 999/ 9,999/ 99,999/ 999,999 lux and an improved accuracy of +/-2% <3000 and +/-6% >3000. Conforms to class AA of JIS C1609-1 2006 “Illumination Meter”. Provides additional computational factors such as average illuminance and luminous intensity.

Wide measurement range, high accuracy  0.0-999,000lux  +/-2% rdg
Spectral response characteristics for visible range
Good oblique incident light characteristics
Excellent visible region relative spectral response—The relative spectral response of the lux meter shouldideally be the same degree of brightness as V(λ),which is the unit of brightness to which human beings are considered sensitive. In the JIS standard, the system ofevaluating the characteristics of the visible region relative spectral response is adopted in order to bring the relativespectral response of the lux meter much closer to thisideal. The following diagram shows the relative spectral response (typical response) of the 510 series lux meterwhich conforms to this system.
Oblique incident light measurement— To measure the intensity of illumination from a light source in anoblique direction accurately, there is a necessity that the angle of incidence to the perpendicular line from the target of the surfaceis in proportion to the cosine law.

510 series lux meter measures the intensity of illumination more accurately because its sensitivity approximates to thestandard spectral luminous efficiency which is the same sensitivity as the human eye. However, since spectral characteristics differdepending on the light source types, a subtle indication error occurs.
Average Illuminance Computation Function automatically calculate 4 or 5 points average of illumination.JIS C 7612 [Illuminance Measurements for Lighting Installations] describes how to calculate the average illuminance using the4-point and 5-point methods.
Response switching, Range Hold, Timer Hold, Deviation display, Auto power off, Color correction factor setting,Average illuminance computation, Ripple measurement, Light source luminous intensity measurement, Measurement of totalized intensity of illumination

Product Includes    Instruction manual; dry cell (builit in); soft case; recorder output plug
Specifications
Photoelectric element Silicon photodiode Display Liquid crystal display (number of 7 digits); maximum effective display:999; (0 or 0’s to indicate the number of digits) Measurement cycle Twice per second Measuring range 0.0 to 99.9/999/9,990/ 99,900/999,000lx Accuracy(*) ±4% rdg ±1dgt (under 3000lx) ±6% rdg ±1dgt (over 3000lx) Response time Automatic range : 5 sec; Manual range: 2 sec Characteristics of oblique incident light
Angle of :
10° ±1%
30° ±2%
50° ±6%
60° ±7%
80° ±25%
(deviation from cosine characteristics)
size    67(W) x 177(H) x 38(D) mm
Shipping Weight    3.0000
Power Supply    AA (LR6) x 2 OR USB supply (5 VDC ±5%)
Manufacturer    Yokogawa
MPN    51021
Manufacturer Warranty    1 Year