PASCO PS-2122 User Manual

Tu rb id it y S en so r

PASPORT Extension

Cable

NTU 100 Standard

(6 mL bottle)

6 mL Cuvette

and Cap
(5 each)

PS-2122 Turbidity

Sensor

Calibration

Button

Sample

Compartment Lid

PS-2122

Instruction Sheet

012-08162D

Included Items Included Items

Turbidity Sensor (PS-2122) PASPORT Extension Cable (PS-2500)
NTU 100 Standard (PS-2511) Cuvette, 6 mL, with Cap (5 each)
Cuvette Cap Labels (not shown) Storage Box (not shown)

Required Items* Required Items*

PASCO Interface PASCO Data Acquisition Software

*See the PASCO catalog or the PASCO web site at
www.pasco.com for more information.

Product Description

The PS-2122 Turbidity Sensor is designed to measure the
turbidity level (“cloudiness”) of water samples in nephelo-

metric turbidity units (NTU) by measuring light scattered
by the sample at 90 degrees. The light source is stabilized
to prevent drift. The opaque housing eliminates ambient
light.

The Turbidity Sensor is intended for educational purposes
and is not recommended for environmental compliance
testing or similar activities.

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Model No.PS-2122 Product Description

Sensor

PASPORT

Input Port

Interface



The Turbidity Sensor makes relative measurements of tur­bid solutions with a particle size between 0 and 200
microns. Because turbidity is a time-dependent dynamics
phenomenon, factors such as particle density, particle size,
temperature, and pressure may cause reading variation,
especially in repeatability studies. For particle sizes above
200 microns, extract the large particles or allow more time
for measurement.

Suggested Activities

• Compare the turbidity of water sample from various
locations.

• Determine the rate of settling of a sample.

• Measure the formation of a precipitate.

Quick Start

• Plug the Turbidity Sensor into one of the PASPORT
input ports of a PASCO interface (such as the 850 Uni­versal Interface or SPARK Science Learning System).

Calibration

Preparation Procedures: Regular Use

Calibration of the Turbidity Sensor is required the first
time the sensor is used. It is also necessary when you are
measuring solutions with varying temperatures, or when
using different cuvettes. All calibrations are stored inside
the sensor in flash memory.

• To prepare for calibration of the Turbidity Sensor, gen­tly invert the 100 NTU Standard cuvette (included) five
times. Clean the outside of the cuvette.

• Put 6 mL of deionized water into an empty cuvette and
tighten the cap. Clean the outside of the cuvette.

• Connect the sensor to a P ASPORT -compatible interface.

• NOTE: If more distance is needed between the sensor
and the interface, connect the sensor to the PASPORT
Extension Cable (PS-2500) and then plug the cable into
the interface.

• Put 6 milliliters (mL) of a fluid sample in a cuvette and
cap it. NOTE: Avoid touching the glass with your fin­gers. Wipe the glass with a non-abrasive cleaning tissue
and/or silicone oil.

• Put the sample cuvette into the Sample Compartment
and close the lid.

• Start the PASCO data acquisition software (such as
PASCO Capstone). Set up a data display in the software.

• Put the cuvette with the deionized water into the sensor
Sample Compartment and close the lid.

Calibration

• Press and release the green Calibration Button on the
sensor.

• The light-emitting diode (LED) in the button will come
on.

• In a moment, the LED in the button will begin to blink.
After a few moments of blinking, press the green button
again to stop the blinking.

• Replace the first cuvette with the 100 NTU Standard
cuvette and close the lid

• Press and release the green button. After the LED
begins to blink, press the button again to stop the blink­ing.

• T o verify, start the PASCO data acquisition software, set
up a Digits display, and start recording data.

• Begin recording data.

SETUP: For more information on setting up the software
and recording data, refer to the User’s Guide and online
help for the data acquisition software.

• The Digits display should show approximately 100
NTU ±1 NTU.

• Stop recording data.

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Model No.PS-2122 Product Description

Sample Compartment

Lid

Cap Label
with Arrow

Screw

Preparation Procedures: Intermittent Use

If the 100 NTU Standard cuvette has been stored for more
than one month, do the following before calibration:

1.Shake the cuvette vigorously for one minute to stir up

the particles.

2.Allow the cuvette to stand undisturbed for five minutes

to eliminate air bubbles.

3.Gently invert the cuvette five times.

4.Clean the outside of the glass cuvette.

Expiration

By following the preparation procedures, the 100 NTU
Standard sample should provide accurate results (±7%) up
to the expiration data on the bottom of the cuvette. After
the expiration date, PASCO cannot guarantee the stability
of the sample. Order PS-2511 to replace the 100 NTU
Standard sample.

4.With your covered hand, rotate the cuvette while
observing the reading in the display. At the lowest tur­bidity reading, stop recording data. Do not rotate the
cuvette any further. St op recording data.

5.With the cuvette still in the Sample Compartment, place
one of the provided arrow labels on the cap, with the
arrow pointing toward the screw on the front of the
Sample Compartment.

For subsequent measurements, always align the arrow
with the screw. Do not switch caps between cuvettes.

Sensor Usage Tips

• For very turbid samples, the initial turbidity measure­ment will fluctuate as particles begin to settle. Wait for
the reading to stabilize and then record the measure­ment.

• Avoid taking readings around bright lights. Make sure
that the lid is closed securely.

• Avoid or dilute dark-colored samples.

• Always fill the cuvette to the lid with at least 6 mL of
sample.

• Before making a turbidity reading, use a sieve or pipette
to remove “floaters” or large, visible particles of sedi­ment from the sample

Orienting the Cuvette (Optional)

To minimize variations in th e readings due to natu ral dif­ferences or imperfections in the glass of the cuvette, do the
following for each cuvette you plan to use:

Specifications

Item Information
Range: 0 to 400 NTU*
Accuracy: ± 0.2 NTU for 0 to 20 NTU

± 0.5 NTU for 20 to 100 NTU

±1 NTU for 100 to 400 NTU
Resolution: 0.1 NTU
Temperature Range: 5 to 40 °C

*1 NTU = one nephelometric turbidity unit

Other Items

Cuvettes and Caps PS-2509 (set of 6 each)
Silicone Oil* PS-2510

*Use the Silicon Oil to wipe the outside of the glass cuvette.

1.Insert the cuvette containing 6 mL of a sample into the

Sample Compartment, but do not close the lid. Instead,
grasp the cap of the cuvette.

2.Put a piece of black cloth over your hand and the sensor

so that no light enters the sensor.

3.Set up a Digits display in the data acquisition software.

Start recording data.

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Turbidity Sensor Product Description

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.)
Web: www.pasco.com
Email [e-mail]

For the latest information about the Turbidity Sensor, visit
the PASCO web site at www.pasco.com and enter
“PS-2122” in the Search window.

Limited Warranty For a description of the product warranty, see the
PASCO catalog. Copyright The PASCO scientific 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 Capstone,
PASPORT, SPARK Science Learning System, SPARK SLS, and
SPARKvue 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.

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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