PASCO PS-2117 Drop Counter - Manual (Page 4)

D r o p C o u n t e r S p e c i f i ca t i o n s
4
Tips
•
Except for opening and closing the stopcocks, do not
touch the syringe during the titration; otherwise, the
drop size may change significantly.
• The drop rate must remain approximately constant
(about 2 drops per second) in order for the drop size to
remain constant.
• Drop size depends on the exact position of the bottom
stopcock. Therefore, the average drop size will be dif-
ferent for every titration. For each titration, re-enter the
volume used and drop count values in the calculation.
Other Titrations
Titrations with different solutions can be performed using
the same equipment and procedure. Other probes (such as
conductivity or ORP) can be used in place of the pH probe.
Theory of Operation
The Drop Counter
uses an infrared light
source and a photo-
detector. Lenses
spread the light into a
“sheet” and refocus it
onto the photodetec-
tor. When a drop of
fluid passes through the Drop Counter, it partially blocks this
sheet of light, and the photodetector registers a momentary
decrease in light intensity.
The Drop Counter uses infrared light and ignores visible
light. On power up, it automatically adjusts the light level for
the best sensitivity. Use the Drop Counter away from direct
sunlight or other sources of infrared that may interfere with
it.
Troubleshooting
Specifications
Technical Support
For assistance with any PASCO product, contact PASCO at:
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 laborato-
ries and classrooms, and are not sold for profit. Reproduction under
any other circumstances, without the written consent of PASCO sci-
entific, is prohibited. Trademarks PASCO, PASCO Capstone,
PASPORT, SPARK Science Learning System, SPARK SLS, and
SPARKvue are trademarks or registered trademarks of PASCO sci-
entific, in the United States and/or in other countries. For more infor-
mation 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 pur-
chased the product.
The European Union WEEE (Waste Elec-
tronic 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 con-
tainer.
Problem Cause Solution
Indicator light
flashes twice for a
single drop. Drop
Counter registers
more drops than
actually dispensed. Fluid is splashing
back into the
drop window. Adjust the position
of the beaker, Drop
Counter, or syringe
to eliminate splash
back
Indicator LED
remains on
constantly. Drop
Counter does not
register drops. Lenses in drop
window are dirty
or wet. Clean lenses with
water and dry with a
cotton swab or
tissue.
detector
collimating
lens
focusing
lens
sheet of light
drop infrared light
source
Item Value
Range: -35 to 135°C
Accuracy: ±0.5°C
Resolution: 0.01°C or better
Response TIme Wait 15 seconds for stable readings
in liquids, and wait 30 to 60 seconds
for stable readings in gases.
Address: PASCO scientific
10101 Foothills Blvd.
Roseville, CA 95747-7100
Phone: +1 916-786-3800 (worldwide)
800-772-8700 (U.S.)
E-mail: [email protected]
Web www.pasco.com