PASCO PS-3517 User manual

Carbon Dioxide ISE Probe (PS-3517)
Introduction
The Carbon Dioxide Ion Selective Electrode (ISE) Probe is a
gas-sensing electrode that allows fast, simple, economical, and
accurate measurement of dissolved CO2in aqueous solutions.
Components
Internal glass electrode
The sensing element of the ISE Probe.
BNC connector
Use this to connect the probe to a pH sensor, such as the
Wireless pH Sensor (PS-3204), via the included BNC
cable.
Membrane module
Holds the Internal Fill Solution which is used in the
assembled electrode.
Storage bottle
Contains storage solution used to preserve the functionality
of the electrode while not in use. See Electrode storage
for more information on storing the electrode.
Included equipment and solutions:
•Carbon Dioxide Electrode
•Storage bottle
•Membrane module (2x)
•BNC male-to-BNC male cable
•Internal Fill Solution
•1000 ppm Carbon Dioxide Standard Solution
•Ionic Strength Adjuster (ISA)
•Pipette
Required equipment and solutions:
•Wireless pH Sensor (PS-3204)
NOTE: You can also use the PASPORT High
Precision pH/Temperature with ISE/ORP
Amplifier (PS-2147) and a compatible
PASPORT interface. However, unlike the
Wireless pH Sensor, the PASPORT
pH/Temperature sensor does not have direct
concentration reading capabilities.
•PASCO Capstone or SPARKvue data collection software
•Wash bottle filled with distilled or de-ionized (DI) water
•pH 4.0 Buffer Solution
•pH 7.0 Buffer Solution
•Lab wipes
•Clean volumetric flasks (100 mL)
•Clean beakers
Get the software
You can use the Carbon Dioxide ISE Probe with SPARKvue or
PASCO Capstone software. If you’re not sure which to use, visit
pasco.com/products/guides/software-comparison.
SPARKvue is available as a free app for Chromebook, iOS, and
Android devices. We offer a free trial of SPARKvue and
Capstone for Windows and Mac. To get the software, go to
pasco.com/downloads or search for SPARKvue in your device’s
app store.
If you have installed the software previously, check that you have
the latest update:
SPARKvue
Go to Main Menu > Check for Updates
PASCO Capstone
Go to Help > Check for Updates.
Using Ionic Strength Adjuster (ISA) solution
to improve accuracy
At low concentrations of CO2ions, a standard method for
removing the influence of charged particles on the detector is to
add Ionic Strength Adjuster (ISA) solution to each of your
standard solutions and samples. The addition assures that the
overall ion activity in each solution being measured is nearly
equal. The ISA contains no ions common to the Carbon Dioxide
ISE itself.
Electrode assembly
IMPORTANT! Please read these instructions before
assembling the Carbon Dioxide ISE Probe!
1. Carefully remove the internal glass electrode from the
storage bottle. Set the storage bottle aside for later use.
NOTE: Soaking the internal glass electrode in
Internal Fill Solution or pH 4.0 buffer for at least
1 hour before proceeding with the following
steps will ensure fast response.
2. Fill one of the membrane modules with approximately
0.75 mL of the provided Internal Fill Solution.
3. Rinse the internal glass electrode with DI water and blot
dry. Place the electrode into the membrane module filled
with Internal Fill Solution and tighten the cap until snug. Do
not over-tighten.
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Set up the electrode
NOTE: These procedures use the Wireless pH
Sensor (PS-3204). For information on
connecting a different pH sensor to PASCO
Capstone or SPARKvue, consult the manual for
the sensor and the Capstone or SPARKvue
online help. The PASPORT High Precision
pH/Temperature with ISE/ORP Amplifier
(PS-2147) cannot be directly configured as a
Carbon Dioxide ISE.
1. Prepare the electrode as described in Electrode
assembly.
2. Connect the electrode to the Wireless pH Sensor using the
attached BNC cable, then turn on the sensor.
3. Start PASCO Capstone or SPARKvue.
To connect the Wireless pH Sensor to the computer and
configure it as a Carbon Dioxide ISE, follow the steps below for
your chosen program.
SPARKvue:
4. Click Sensor Data.
5. From the list of available wireless devices, select the pH
sensor matching your device’s printed ID number (XXX-
XXX) to connect to the sensor.
6. Under the list of measurements for the pH sensor, click
Configure ISE and select Carbon Dioxide (aqueous) ISE
from the list of ISE options.
PASCO Capstone:
4. Select Hardware Setup from the Tools palette.
5. From the list of Available Wireless Devices, select the pH
sensor matching your device’s printed ID number (XXX-
XXX) to connect to the sensor.
6. Click Properties next to the sensor’s name.
7. From the Properties menu, click the dropdown box next to
ISE Configuration, then select Carbon Dioxide
(aqueous) ISE.
Checking electrode slope
The following procedure allows you to check the electrode slope
of your sensor. This process is used to ensure your sensor is
recording accurate measurements. It is recommended that you
perform this test once every few years to check your sensor’s
functionality.
1. Connect the electrode to the Wireless pH Sensor (or
equivalent), then connect the sensor to PASCO Capstone
or SPARKvue.
2. In Capstone or SPARKvue, create a Digits display
measuring the electric potential (Voltage) in millivolts (mV).
NOTE: See the PASCO Capstone or SPARKvue
online help for more detailed instructions on
setting up displays and other aspects of the data
collection process.
3. Place 80 mL of DI water into a 100 mL volumetric flask.
Add 1 mL of the provided ISA solution and invert the flask
repeatedly to mix.
4. Check the pH of the water using lab pH paper. The pH
value must be between 4.0 and 4.5. If it is not, add
additional ISA in 1 mL increments until the pH value is
between 4.0 and 4.5.
5. Add 10 mL of 1000 ppm Carbon Dioxide Standard Solution
into the flask. Fill the flask to the 100 mL line with DI water
and invert flask several times to mix.
6. Rinse the electrode tip with DI water and blot dry.
7. Pour the resulting solution into a 100 mL beaker. Immerse
the electrode tip into the prepared solution to a depth of at
least one inch.
TIP: To prevent air entrapment on the
membrane surface, use an electrode holder to
keep the electrode at a 20 degree angle away
from vertical.
8. Begin recording data and wait for a stable reading to be
displayed. (This may take several minutes.) Record this
potential (E1) in mV.
9. In a separate 100 mL beaker, place 10 mL of the solution
from the first beaker, then fill to the 100 mL mark with DI
water. Stir thoroughly.
10. Remove the electrode from the first beaker. Rinse the
electrode tip with DI water and blot dry.
11. Immerse the electrode tip into the second prepared solution
to a depth of at least one inch.
12. Begin recording data and wait for a stable reading to be
displayed. Record this potential (E2) in mV.
13. The difference between the first and second potential
readings, (E1- E2), is defined as the slope of the electrode.
At a standard room temperature of 25 °C, the normal range
for this slope is 56±4 mV.
Troubleshooting the electrode slope
If the electrode slope is not within the normal range stated
above, or the electrode mV reading drifts, the Internal Fill
Solution may need to be refilled. Follow the procedures outlined
in Electrode assembly. If this does not fix the problem, check
the slope of the internal glass electrode through the following
procedure:
1. Remove the membrane module from the electrode body.
2. Rinse the internal glass electrode with DI water and blot
dry.
3. Connect the probe to the Wireless pH Sensor (or
equivalent), then connect the sensor to SPARKvue or
PASCO Capstone as described in Set up the electrode.
4. Create a Digits display measuring the potential in mV.
5. Immerse the internal glass electrode in a beaker of pH 7.0
buffer. Make sure the annular ceramic junction of the
internal glass electrode is submerged.
6. Begin data recording. Once the reading has stabilized,
record the potential in mV.
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7. Remove the internal glass electrode from the pH 7.0 buffer.
Rinse the electrode with DI water and blot dry.
8. Immerse the internal glass electrode in a beaker of pH 4.0
buffer.
9. Begin data recording again. Once the reading has
stabilized, record the potential in mV.
The potential reading in pH 7.0 buffer should be 0±25 mV. The
potential difference between the two readings should be greater
than 168 mV. If the difference is less than 160 mV, consider
replacing the sensor. Contact PASCO if the sensor is still within
the warranty (1 year from purchase), or purchase a new sensor.
If the internal glass electrode functions properly but the
completely assembled electrode does not, replace the
membrane module with a new one filled with Internal Fill
Solution. A spare membrane is included with the electrode.
Follow the steps under Check electrode operation (slope)
again after replacing the membrane.
NOTE: All solutions should be prepared fresh.
For best performance, use ISA in all solutions.
Reading samples with the electrode
Various procedures may be used to determine the concentration
of a sample. The most common is the Direct Calibration method,
which is described in the following sections. Contact PASCO’s
Technical Support department for details of other methods.
In Direct Calibration, a series of standard solutions of differing
concentration is used to calibrate the electrode. From there,
each sample requires only a single reading, which is compared
with the calibration readings to obtain the sample concentration.
ISA is added to all solutions to ensure that the samples and
standards have very similar ionic strength and pH.
Measurement set-up
1. Prepare the electrode as described in Electrode
assembly.
2. Connect the electrode to PASCO Capstone or SPARKvue
and configure it as a Carbon Dioxide ISE, as described in
Set up the electrode.
3. Prepare two standards that differ in concentration by a
factor of ten and bracket the expected sample
concentration range. Both standard solutions can be
obtained by diluting the 1000 ppm Standard Solution
(provided with the electrode) in DI water. For example, if
your expected sample concentration is 50 ppm carbon
dioxide, dilute 10 mL of the 1000 ppm standard solution in
a 100 mL volumetric flask to obtain a 100 ppm high
standard, then dilute 10 mL of the high standard in an
identical flask to obtain a 10 ppm low standard. All samples
and standard solutions should be at the same temperature.
Calibrating with direct concentration reading
Follow the procedures below for your program of choice if using
a pH sensor with direct concentration reading capabilities, such
as the Wireless pH Sensor (PS-3204).
SPARKvue:
1. From the Sensor Data screen, check the box next to
Carbon Dioxide (aqueous) ISE in the list of available
measurements, then select a template to open the
Experiment Screen.
2. From the Live Data Bar on the bottom left of the
Experiment Screen, click on Carbon Dioxide (aqueous)
ISE and select Calibrate measurement from the list.
3. Make sure that the following settings are selected in the
Calibrate Sensor window:
-Sensor: {Name of the sensor you are using}
-Measurement: Carbon Dioxide (aqueous) ISE (mg/L)
-Calibration Type: 2 point (Adjust Slope and Offset)
4. Click Continue.
5. Remove approximately 10 mL of your low standard solution
from its volumetric flask and set it aside until Step 7. Add
1 mL of ISA to the flask and invert repeatedly to mix.
6. Use lab pH paper to check the pH of the standard. The
value must be between 4.0 and 4.5; if it is not, add ISA in
1 mL increments and continue mixing until the value is
within this range.
7. Fill your flask to the 100 mL mark with the low standard
solution that you removed in Step 5. (If you do not have
enough solution to reach the 100 mL mark, simply add all
of the removed solution.) Invert repeatedly to mix, then
pour the entire solution into a 150 mL beaker.
8. Rinse the electrode with DI water, blot dry, and place it into
the beaker. Wait for a stable reading in the Current Value
boxes. (This may take several minutes.)
9. Enter the known concentration of the low standard solution,
in mg/L, into the Standard Value box under Calibration
Point 1, then click Set Calibration.
TIP: For solutions dissolved in DI water, 1 ppm
and 1 mg/L are approximately equivalent.
10. Remove the electrode from the low standard solution
beaker. Rinse the electrode with DI water and blot dry.
11. Remove approximately 10 mL of your high concentration
standard from its volumetric flask and set aside until the
next step. Add 1 mL of ISA to the flask and invert to mix.
12. Repeat Step 6 for the high standard solution, then fill the
flask to the 100 mL mark with the high standard solution
removed in the previous step. Invert to mix, then pour the
solution into a new 150 mL beaker.
13. Place the electrode into the high standard solution beaker
and wait for a stable reading in the Current Values boxes.
14. Enter the known concentration of the high standard
solution, in mg/L into the Standard Value box under
Calibration Point 2, then click Set Calibration.
15. Review your new calibration, then click OK.
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PASCO Capstone:
1. Select Calibration from the Tools palette.
2. Select Concentration from the list of measurements, then
click Next.
3. Ensure that Two Standards (2 point) is selected from the
list of calibration types, then click Next.
4. Remove approximately 10 mL of your low standard solution
from its volumetric flask and set it aside until Step 6. Add
1 mL of ISA to the flask and invert repeatedly to mix.
5. Use lab pH paper to check the pH of the standard. The
value must be between 4.0 and 4.5; if it is not, add ISA in
1 mL increments and continue mixing until the value is
within this range.
6. Fill your flask to the 100 mL mark with the low standard
solution that you removed in Step 4. (If you do not have
enough solution to reach the 100 mL mark, simply add all
of the removed solution.) Invert repeatedly to mix, then
pour the entire solution into a 150 mL beaker.
7. Rinse the electrode with DI water, blot dry, and place it into
the beaker. Wait for a stable reading in the Current Value
box. (This may take several minutes.)
8. Enter the known value of the concentration, in mg/L, into
the Standard Value box and click Set Current Value to
Standard Value.
TIP: For solutions dissolved in DI water, 1 ppm
and 1 mg/L are approximately equivalent.
9. Remove the electrode from the low standard solution
beaker. Rinse the electrode with DI water and blot dry.
10. Remove approximately 10 mL of your high concentration
standard from its volumetric flask and set aside until the
next step. Add 1 mL of ISA to the flask and invert to mix.
11. Repeat Step 5 for the high standard solution, then fill the
flask to the 100 mL mark with the high standard solution
removed in the previous step. Invert to mix, then pour the
solution into a new 150 mL beaker.
12. Place the electrode into the high standard solution beaker
and wait for a stable reading in the Current Values boxes.
13. Enter the known concentration of the high standard
solution, in mg/L into the Standard Value box and click Set
Current Value to Standard Value.
14. Review your new calibration and click Finish.
Calibrating with millivolt reading
Follow this procedure only if you are using the PASPORT High
Precision pH/Temperature with ISE/ORP Amplifier.
1. Connect the sensor to a compatible PASPORT interface,
such as the 550 Universal Interface (UI-5001), and connect
the interface to SPARKvue or PASCO Capstone.
2. Create a Digits display measuring the potential reading, in
mV, from the sensor.
3. Remove approximately 10 mL of your low standard solution
from its volumetric flask and set it aside until Step 6. Add
1 mL of ISA to the flask and invert repeatedly to mix.
4. Use lab pH paper to check the pH of the standard. The
value must be between 4.0 and 4.5; if it is not, add ISA in
1 mL increments and continue mixing until the value is
within this range.
5. Fill your flask to the 100 mL mark with the low standard
solution that you removed in Step 3. (If you do not have
enough solution to reach the 100 mL mark, simply add all
of the removed solution.) Invert repeatedly to mix, then
pour the entire solution into a 150 mL beaker.
6. Rinse the electrode with DI water, blot dry, and place it into
the beaker. Start data collection and wait for a stable
reading. (This may take several minutes.)
7. Once the reading stabilizes, record the potential reading in
mV and the known concentration of the low standard
solution.
8. Remove the electrode from the beaker. Rinse the electrode
with DI water and blot dry.
9. Remove approximately 10 mL of your high concentration
standard from its volumetric flask and set aside until the
next step. Add 1 mL of ISA to the flask and invert to mix.
10. Repeat Step 4 for the high standard solution, then fill the
flask to the 100 mL mark with the high standard solution
removed in the previous step. Invert to mix, then pour the
solution into a new 150 mL beaker.
11. Once the reading stabilizes, record the potential reading
and the known concentration of the high standard solution.
12. Remove the electrode from the beaker, rinse with DI water,
and blot dry.
13. Using semilogarithmic graph paper, prepare a calibration
curve by plotting the recorded millivolt values on the linear
axis and the known concentration values of the standard
solutions.
Measuring with direct concentration reading
After completing Calibrating with direct concentration
reading, measure the sample concentration with these steps:
1. Remove 10 mL of your sample solution from the 100 mL
volumetric flask and set it aside for Step 3. Add 1 mL of ISA
and invert to mix.
2. Use lab pH paper to check the pH of the sample. The value
must be between 4.0 and 4.5; if it is not, add ISA in 1 mL
increments and continue mixing until the value is within this
range.
3. Fill the flask to the 100 mL line with the remaining solution
removed in Step 1. Invert repeatedly to mix, then pour the
solution into a 150 mL beaker for testing.
4. Rinse the electrode with DI water, blot dry, and place it into
the beaker.
5. In the program the sensor is connected to, create a Digits
display measuring the concentration of carbon dioxide from
the ISE Probe.
6. Begin data collection. Once the reading stabilizes, record
the concentration value.
7. Repeat Steps 1 through 6 for any additional samples.
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Measuring with millivolt reading
Follow the below procedures only if you are using the
PASPORT High Precision pH/Temperature with ISE/ORP
Amplifier (PS-2147). After completing Calibrating with millivolt
reading, follow these steps to calculate the concentration of a
sample:
1. Remove 10 mL of your sample solution from the 100 mL
volumetric flask and set it aside for Step 3. Add 1 mL of ISA
and invert to mix.
2. Use lab pH paper to check the pH of the sample. The value
must be between 4.0 and 4.5; if it is not, add ISA in 1 mL
increments and continue mixing until the value is within this
range.
3. Fill the flask to the 100 mL line with the remaining solution
removed in Step 1. Invert repeatedly to mix, then pour the
solution into a 150 mL beaker for testing.
4. Rinse the electrode with DI water, blot dry, and place it into
the beaker.
5. In the Digits display used for calibration, resume data
collection. Once the reading stabilizes, record the potential
value in mV.
6. Determine the sample concentration using the calibration
curve you created in Calibrating with millivolt reading
and the mV value obtained in Step 5.
7. Repeat Steps 1 through 6 for any additional samples.
Electrode storage
Short-term
Between measurements, keep the electrode tip immersed in a
10 ppm standard without ISA. For overnight storage, immerse
the electrode tip in a pH 7.0 buffer.
Long-term
For storage of one week or more, disassemble the electrode
completely. Rinse the membrane module and the tip of the
internal glass electrode with DI water and blot dry. Cover the tip
of the internal glass electrode with the original storage bottle.
Store all parts securely in the original box. When reassembling,
follow the procedure in Electrode assembly, as well as
Checking electrode operation if the sensor has been stored for
several months or more.
Software help
The SPARKvue and PASCO Capstone Help provide additional
information on how to use this product with the software. You
can access the help within the software or online.
SPARKvue
Software: Main Menu > Help
Online: help.pasco.com/sparkvue
PASCO Capstone
Software: Help > PASCO Capstone Help
Online: help.pasco.com/capstone
Specifications and accessories
Visit the product page at pasco.com/product/PS-3517 to view
the specifications and explore accessories. You can also
download support documents from the product page.
Technical support
Need more help? Our knowledgeable and friendly Technical
Support staff is ready to answer your questions or walk you
through any issues.
Chat pasco.com
Phone [phone] x1004 (USA)
[phone] (outside USA)
Email [e-mail]
Regulatory information
Limited warranty
For a description of the product warranty, see the Warranty and Returns page at
www.pasco.com/legal.
Copyright
This document 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 and PASCO scientific are trademarks or registered trademarks of PASCO
scientific, in the United States and in other countries. All other brands, products, or
service names are or may be trademarks or service marks of, and are used to
identify, products or services of, their respective owners. For more information visit
www.pasco.com/legal.
Product end-of-life disposal
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 or disposal
service, or the place where you purchased the product. The European Union
WEEE (Waste Electronic and Electrical Equipment) symbol on the product or its
packaging indicates that this product must not be disposed of in a standard waste
container.
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