User's Manual

ManualsBrandsPASCO Specialty & Mfg. ManualsMarine InstrumentsPASCO Specialty & Mfg. Light Level Sensor PS-2177

Instruction Sheet

012-11060A

Light Level Sensor

PS-2177

*012-11060*

*See the PASCO catalog or web site at www.pasco.com for compatible PASPORT interfaces and Data Acquisition Software..

Introduction

Photometry deals with the measurement of visible light as perceived by human eyes. The PASPORT Light Level

Sensor measures illuminance in lux. The readings of the sensor mimic the wavelength sensitivity of the human

eye, which is most sensitive in the green part of the spectrum (peaking at about 555 nanometers). This is

achieved with a green filter in the sensor.

In photometry, illuminance is the luminous flux incident on a surface, per unit area. In other words, it is the mea-

sure of the intensity of the incident light, wavelength-weighted to correlate with human brightness perception.

Illuminance is measured in lux, or lumens per square meter. Luminous flux, measured in lumens, is the perceived

power (energy per unit of time) of light. One lumen is defined as the luminous flux of light produced by a light

source that emits one candela of luminous intensity over a solid angle of one steradian. Luminous intensity, mea-

sured in candela, is the wavelength-weighted power emitted in a particular direction per unit solid angle. If a

light source emits one candela, a metric (SI) base unit, it emits monochromatic green light with a frequency of

540 terahertz (THz) that has a radiant energy of 1/683 watts per steradian in a given direction. A one-hundred

watt incandescent light bulb emits about 120 candela. A uniform one candela source emits 12.6 lumens.

Included Equipment Part Number

Light Level Sensor PS-2177

Summary of content (4 pages)

PAGE 1
Instruction Sheet 012-11060A *012-11060* Light Level Sensor PS-2177 Eight pin miniDIN connector Range Select Buttons Light Level Sensor Light Dome \ Included Equipment Part Number Light Level Sensor PS-2177 Recommended Items PASPORT Extension Cable PS-2500 PASCO Interface Catalog or web site* Data Acquisition Software Catalog or web site* *See the PASCO catalog or web site at www.pasco.com for compatible PASPORT interfaces and Data Acquisition Software..
PAGE 2
Model No.PS-2177 Introduction About the Sensor The PS-2177 Light Level Sensor uses a silicon photodiode that produces a voltage that is proportional to light intensity. The photodiode has a spectral response range from 320 to 730 nanometers (nm) and a peak sensitivity at 560 nm, which is very close to the peak sensitivity wavelength of the human eye. The maximum dark current is 10 picoamperes at one volt. The accuracy is ±10%.
PAGE 3
Model No.PS-2177 Setup Using the Sensor Hardware Setup • Setup • Point the light dome on the sensor toward the light source. • The default light intensity range is “Light Bulb”. • Select a different range if needed by pressing the button next to the icon. • When a button is pressed, the green LED lights up. Connect the Light Level Sensor to a PASPORT interface. If you will be using a computer, connect the PASPORT interface to the computer’s USB port.
PAGE 4
Light Level Sensor Setup Select a Display To set up a particular display (e.g., digits display), touch BUILD. Touch a quantity from the list, and then touch one of the display icons. Touch OK to open the display, and then touch the Start button to begin collecting data.