PASCO PS-2177 User Manual

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Light Level Sensor

Eight pin mini­DIN connector

Light Dome

Light Level

Sensor

Range Select

Buttons

PS-2177

Instruction Sheet

012-11060A

*012-11060*

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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..

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 mea­sure 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, mea­sured 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.

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Model No.PS-2177 Introduction

PS-2500 PASPORT

Extension Cable

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%.

Light Level Ranges

The sensor has three ranges which can be selected using the range select buttons on
the sensor. The range for each button is represented by an icon.

Icon Light Level Resolution

Candle 0 to 1,500 lux 0.5 lux

Light bulb 0 to 15,000 lux 5 lux

Sun 0 to 150,000 lux 50 lux

Illuminance: Typical Readings

The following table shows typical readings for a variety of conditions

Condition Illuminance (lx) Condition Illuminance (lx)

Sunlight 100,000 Quarter moon 0.01

Full daylight 10,000 Starlight 0.001

Overcast day 1,000 Warehouse 150

Very dark day 100 Offices, labs 500

Twilight 10 Supermarkets 750

Deep twilight 1 Operating rooms 1,000

Full moon 0.1 Detailed drawing work 1,500 to 2,000

Usage

The sensor can be used for a variety of experiments.

• Plant growth versus light intensity.

• Light intensity through polarized filters.

• Amounts of solar energy in various locations.

• Relationship of light intensity versus distance for a point source.

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Model No.PS-2177 Setup

Using the Sensor

• 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.

Start button

Setup

Hardware Setup

• 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.

DataStudio Setup

If you will be using the Light Level
Sensor with a computer, install the lat­est version of DataStudio first. Check
the PASCO web site at
www.pasco.com for information.

1. When you connect the Light
Level Sensor to the computer
through a PASPORT inter­face, the PASPortal window
will launch automatically (if
DataStudio is not already running).

2. Select Launch DataStudio in the PASPortal window.

A Digits display for Light Level measured in lux will open automatically.

3. Click to begin data collection.

To view and change the sample rate and other sensor properties, click to open
the Experment Setup window. The default sample rate is 5 Hz and the maximum sam­ple rate is 1000 Hz.

Xplorer and Xplorer GLX Setup

If you will be using an Xplorer or Xplorer GLX in logging mode (not connected to a
computer), connect the Light Level Sensor to the Xplorer or Xplorer GLX, turn the
interface on, and press to begin data collection.

SPARK Setup

• If the SPARK Science Learning System (SLS) is off, press and hold the power

• Connect the PASPORT sensor to either of the ports on the top of the SPARK. The

Graph Display (default)

To open a graph display, touch any quantity in the list and then touch SHOW to open
PAGE 1. Touch the right arrow next to PAGE 1 to go to the next display (digits).
Touch the Start button to begin collecting data.

button on the bottom to turn it on and then wait for the SPARK to boot up. The
screen will show a message to plug in a sensor.

screen will show the list of quantities measured by the connected sensor.

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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.

Calibration

You do not need to calibrate the Light Level Sensor

Specifications

Accuracy: ±10% Maximum Sample Rate: 1000 Hz

Technical Support

For assistance with any PASCO product, contact PASCO at:

Address: PASCO scientific

10101 Foothills Blvd.
Roseville, CA 95747-7100

Phone: [phone] (worldwide)

800-772-8700 (U.S.)

Fax: [phone]

Web: www.pasco.com

Email: [e-mail]

For more information about the Light Level Sensor and the latest revision of this Instruc­tion Sheet, visit: www.pasco.com/go?PS-2177

Limited Warranty For a description of the product warranty, see the PASCO catalog. Copyright The
PASCO scientific 012-11060A Light Level Sensor Instruction Sheet is copyrighted with all rights
reserved. Permission is granted to non-profit educational institutions for reproduction of any part of this
manual, providing the reproductions are used only in their laboratories and classrooms, and are not
sold for profit. Reproduction under any other circumstances, without the written consent of PASCO sci­entific, is prohibited. Trademarks PASCO, PASCO scientific, DataStudio, PASPORT, Xplorer, and
Xplorer GLX are trademarks or registered trademarks of PASCO scientific, in the United States and/or
in other countries. For more information visit www.pasco.com/legal. Windows is a registered trademark
of Microsoft Corporation in the United States and/or other countries. Mac is trademark of Apple Com­puter, Inc., registered in the U.S. and other countries.

Product End of Life Disposal Instructions:

This electronic product is subject to disposal and recycling regulations that vary by
country and region. It is your responsibility to recycle your electronic equipment per
your local environmental laws and regulations to ensure that it will be recycled in a
manner that protects human health and the environment. To find out where you can
drop off your waste equipment for recycling, please contact your local waste recy­cle/disposal service, or the place where you purchased the product.

The European Union WEEE (Waste Electronic and Electrical Equipment) symbol (to
the right) and on the product or its packaging indicates that this product must not be
disposed of in a standard waste container.

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