vinmetrica SC-300 User manual

SC-300 Pro Kit Manual 1 Version 2.2
Vinmetrica SC-300 Pro Kit™
User Manual
Vinmetrica SC-300*Pro Kit is a simple and robust device that provides high accuracy in determination
of sulfite (SO2), pH and titratable acidity (TA) levels in wines, ciders, and other liquids. These are
essential parameters to control in the effort to make high quality wines. The Pro kit includes lab
accessories for the SC-300 Analyzer.
Table of Contents:
Materials Provided in the Kit...............................................................................................................
Things you will need............................................................................................................................
Why Test for SO2, pH and TA?............................................................................................................
Theory of Operation.............................................................................................................................
Setup....................................................................................................................................................
Setting up the SC-300 for the first time...................................................................................
Assembling the Pro Kit Equipment.........................................................................................
Burette Maintenance................................................................................................................
Burette Reading .......................................................................................................................
Instrument Operation.......................................................................................................................
Procedures...........................................................................................................................................
Measuring Free Sulfite (SO2) by Titration..............................................................................
Measuring Total Sulfite (SO2) by Titration..............................................................................
Calibration of pH .....................................................................................................................
Measuring pH...........................................................................................................................
Measuring Titratable Acidity (TA) by Titration.......................................................................
Finishing up.............................................................................................................................
Warranties, Liabilities & Hazards....................................................................................................
Appendix A - Test Mode.....................................................................................................................
Appendix B - Sulfite & TA Adjustments...........................................................................................
Appendix C1 - Troubleshooting: pH and TA Issues.......................................................................
Appendix C2 - Troubleshooting: SO2Issues...................................................................................
*US Patent pending
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SC-300 Pro Kit Manual 2 Version 2.2
Materials provided in the kit:
1. Vinmetrica SC-300 SO2/pH instrument
(Part number SC-300-1)
2. SO2Electrode (Part number SC-100-3)
3. pH Electrode (Part number SC-200-7)
4. Two 5 mL syringes
5. Two 3 mL polyethylene transfer pipettes
6. One 25 mL serological sampling pipette
7. One 5mL serological sampling pipette
8. 100 mL polypropylene titration beaker
9. SO2Reagent set (Part number SC-100-2):
SO2Titrant solution (0.0156N) Acid reagent Reactant solution
10. pH/TA reagent set (Part number SC-200-8):
pH 4.01 Reference solution pH 7.00 Reference solution TA Titrant (0.133N NaOH)
11. Lab Support stand (Part number SC-300-3)
12. Electrode Holder (Part number SC-300-8)
13. Double Burette Clamp (Part number SC-300-6)
14. 10 mL or 25 mL Glass burette with Teflon Stopcock (with ~2 grams of Burette detergent)
(Part number SC-300-7)
15. Magnetic Stirrer (includes two AA batteries, stir bar and 25 mL cylindrical container)
(Part number SC-300-4)
16. Rinse Bottle (Part Number SC-100-17)
Things you will need:
1. Two standard AA batteries (alkaline type).
2. Distilled water, which usually can be found at your local grocery store (aka purified water by
deionization).
3. (Optional) 1N Sodium Hydroxide solution (if you want to do total SO2). Available from
Vinmetrica (Part number SC-100-7)
Figure 1. The SC-300 instrument

SC-300 Pro Kit Manual 3 Version 2.2
Why Test for SO2, pH and TA?
Testing for sulfite (SO2) is crucially important for making sure your wine does not spoil by
oxidation or from microbial growth. By monitoring your SO2levels, you can make adjustments when
needed, especially before starting primary fermentation, after malolactic fermentation has completed,
after racking or when ready to bottle. To correctly adjust sulfite, you need values for your current free
SO2level and your wine's pH, both of which can be measured with the Vinmetrica SC-300 analyzer.
The key parameter in protecting your wine is molecular SO2which for most wines should be at
0.8 ppm (mg/L) following secondary fermentation. This in turn depends on the free SO2(it can also be
referred to as unbound SO2) and the pH. Overall, you can reach your target molecular SO2by
measuring and adjusting your free SO2levels and considering your wine's particular pH. See Table 1.
Table 1. Free SO2concentrations necessary to attain 0.8 mg/L molecular SO2 at a designated pH.
Free SO2(ppm)
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26
32
40
50
63
79
99
125
pH
3.0
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4.0
We recommend using a sulfite calculator for determining how much sulfite to add to your wines
after taking a sulfite measurement with the SC-300 Pro Kit. Winemaker Magazine's Sulfite Calculator
at http://winemakermag.com/guide/sulfite can walk you through the process. See Appendix B for more
information on how to adjust your wine for sulfite.
Monitoring your wine's pH is also important for the first few months of the wine making
process. Proper pH and Titratable Acidity (TA) levels influence mouth feel and provide wine stability.
During malolactic fermentation, the pH can increase somewhat and should be monitored. Typically,
wine pH and TA are inversely related; when pH goes up, TA goes down and vice versa. Adjustments
may be made to your wine to prevent wine instability. See Appendix B for more information on
adjustments.

SC-300 Pro Kit Manual 4 Version 2.2
Theory of Operation:
1. Sulfite (SO2): The SC-300, with the SO2 electrode and reagents provided, can be used to
determine sulfite (or SO2) levels in wine, musts, and other samples. It relies on the Ripper
titration based on the quantitative reaction of the SO2with iodine (generated during the titration)
which oxidizes the SO2in the sample under acid conditions.
IO3
-+ 5I-+ 6H+3I2+ 3H2O generation of iodine (I2) from iodate (IO3-)
SO2+ I2+ H2O 2I-+ SO3 + 2H+reaction of SO2and iodine
When all the SO2is titrated at the endpoint, excess iodine appears in solution. This is detected
as current with the SO2electrode and signaled by audible and visual indicators. The endpoint is
much more sensitive than the starch color change commonly employed for Ripper titration, and
it is sharp and clear, even when titrating red wines and musts. From the known concentration
of the titrant and its volume required to reach the endpoint, the free SO2is simply calculated.
2. pH and TA: The SC-300 kit also provides a pH electrode and reagents for calibration and
determination of pH and titratable acidity (TA) values in wines and other samples. The pH
value is simply determined by placing the calibrated pH electrode into a sample and reading the
value. TA is determined by titrating a 5 mL sample of wine to an endpoint pH of 8.2* with the
TA titrant (0.133N NaOH) from the syringe in the kit. From the known concentration of the TA
titrant and its volume required to reach the endpoint, the TA is simply calculated (results are in
units of g/L tartaric acid).
3. Potential measurements: In firmware versions 3.1.1 and higher, the SC-300 can display the
voltage reading on an electrode attached to the pH connector. This can be used with certain
electrodes, for example, Vinmetrica’s Dissolved Oxygen System, potassium, or sodium
electrodes, or to view the raw voltage reading of a pH electrode.
*In some countries, pH 7.0 is taken as the endpoint; see Instrument Operation, Step 6 (page 11).

SC-300 Pro Kit Manual 5 Version 2.2
Setup:
Setting up the SC-300 for the first time:
1. The SC-300 (See Figure 1) runs on two standard AA batteries (alkaline cells recommended). To
insert the batteries, open the battery housing on the bottom of the back of the unit by removing
the two screws and gently prying off the lid. Install the batteries, then close the housing. If
desired, you can prop the unit up using its folding stand.
2. Low Battery Detection: When the battery level is getting low, the instrument shows a low
battery icon on the upper left side of the display but continues to operate without impairment of
any function. Replace the batteries as soon as practicable. When the battery level drops too far,
the instrument does not operate. It rapidly flashes the low battery icon for 3.0 seconds, beeps
and shuts itself off.
3. Auto Shut-off: The SC-300 shuts off after 30 minutes. If this happens unexpectedly, just press
the POWER button to resume from where you were.
4. Electrodes: When directed to do so, attach the desired electrode (SO2or pH, Figures 2 & 3) via
the proper connector protruding from the top (on earlier model SC-300s, there is just a single
connector for both electrodes). Your electrodes and/or instrument may have different connectors
than what is shown in the figures below. Be sure to secure the electrode plug to the BNC
connector to insure proper function.
5. SO2electrode: Remove any protective cover from the electrode tip (most electrodes are
shipped without one). This cover need not be used routinely.
Put the electrode on its side, or hang it from the electrode holder if you have one. The SO2
electrode is sturdy with its plastic housing, but do take care not to let things touch or strike the
platinum wires; they are somewhat fragile and will break if bent and straightened repeatedly.
Figure 2. Attach the SO2 electrode
to the connector on the SC-300.
Figure 3. Be sure the pH electrode
attachment is screwed into place
on the BNC connector.

SC-300 Pro Kit Manual 6 Version 2.2
Electrode care: When done, always rinse with DI water and let air dry. There is no need to
store the SO2electrode in any kind of solution.
6. pH electrode: The pH electrode is fragile and should always be handled carefully. Remove the
liquid storage bottle from the electrode by unscrewing the cap first, then gently removing the
bottle and pulling off the cap. Rinse the electrode with a little distilled water before each use.
Electrode care: Do not touch the glass bulb, nor attempt to wipe it with anything. When necessary, you
may gently blot excess liquid away from the electrode surface, but avoid directly touching it. Rinse the
electrode with DI water and gently blot or shake off excess water. Push the electrode through the hole
in the cap about an inch, then gently screw the bottle onto the cap so that the electrode is in contact
with the solution in the bottle. If you happen to spill your pH electrode storage solution, your pH 4.01
solution (SC-200 pH/TA Reagents) can be used as a temporary storage solution but you should order
more pH electrode storage solution as soon as possible. The pH electrode should always be kept in
the liquid storage bottle with its pH electrode storage solution (Part Number SC-200-10) when
not in use.
Note: It is recommended to replace your pH electrode storage solution once a year or if the solution
becomes cloudy or moldy.
Assembling the Pro Kit Equipment:
Remove the items from their packaging: the Lab Support Stand, the Electrode Holder, the
Double Burette Clamp, the Glass Burette, Rinse Bottle and the Magnetic Stirrer. Carefully pull
out the glass burette from its cardboard cylindrical container and out of its container. Use
caution not to exert too much force on the burette as it is fragile and can break.
Open the Magnetic Stirrer from its packaging, then insert the double AA batteries included. We
recommend you do not use the cylindrical container provided with the magnetic stirrer but use
the 100mL titration beaker (Figure 4) included with the SC-300.
Assemble the Lab Support Stand by attaching the long metal rod and screwing it into the large
metal base. We have found that adding a drop of super glue to the threads of the metal rod can
prevent loosening of the assembly. Then place the magnetic stirrer below the lab support stand
as shown below in Figure 4.
To attach the Electrode Holder, loosen the thumb screw on the Holder and slide it onto the Lab
Support Stand rod (Figure 5), then tighten the thumb screw to adjust it to an appropriate height
(Figure 6). Make sure the thumb screw is on the left side of your set up.
Attach the Double Burette clamp to the Lab Support Stand using its thumb screw to adjust for
height, as shown in Figure 7 below. Place the Double Burette Clamp a few inches above the
electrode holder.

SC-300 Pro Kit Manual 7 Version 2.2
Carefully open the Double Burette Clamp's spring arms with your thumb and forefinger and
place the burette in between the four indentations in the double burette clamp's spring arm's
plastic knobs (Figure 8 below). Slowly release the clamp spring to secure the burette between
these four spring arm plastic knobs. You can adjust the burette at any time by raising and
lowering it within the spring arm clamps of the Double Burette Clamp. When making these
adjustments, hold onto the burette and do not apply too much force to it as the burette is
delicate. Use the end of the Electrode Holder as a guide for the tip of the burette (Figure 9).
DO NOT try and force the burette into the cutout at the end of the electrode holder. This
may cause your burette to snap and break. Finally, insert the electrode that you wish to use into
one of the open side slots. Once the black rubber neck of the electrode is sitting on top of the
electrode holder, stabilize the electrode holder and then press the electrode down so the
electrode is further stabilized into the slot. Remember to be gentle with the electrode.
You are now ready to titrate!
Note: The magnetic stir bar that is placed within the 100 mL titration beaker can potentially
damage the SO2and pH electrodes. When adjusting the height of the electrodes, make sure that
the stir bar in the beaker is below the bottom of the electrode. You do not want the spinning
magnetic stir bar to strike the SO2or pH electrode. When titrating for SO2or TA, you can add a
few milliliters of distilled water to raise the liquid level in the titration beaker by a half inch or
so.
Figure 4. The Magnetic
stirrer and beaker with the
pH electrode inserted into
the Electrode Holder
to the wine sample.
Figure 5. The Electrode
Holder slides onto the Lab
Support Stand.
Figure 7. The Double
Burette Clamp slides
easily onto the Lab
Support Stand.
Figure 6. The thumb
screw makes adjusting
The Electrode Holder's
height easy.

SC-300 Pro Kit Manual 8 Version 2.2
Burette Maintenance
Keep the burette clean and wash with deionized (distilled) water when you are finished using
the burette. This is especially important for TA titrations because the TA Titrant is caustic and can etch
the burette. Every so often, you will want to clean your burette with a cleaning solution to maintain
accuracy of the burette. The included ~2 grams of Burette Detergent is specially formulated to clean
glassware. The dry detergent ships in an Eppendorf tube that has markings with approximate half gram
increments. Upon first receiving the detergent, mix approximately half a gram (about an 1/8th of a
teaspoon) with about 50 milliliters (mL) of distilled water into a small bottle. We recommend capping
the bottle and shaking well for a minute or until the detergent is dissolved. Bubbles may form but the
detergent will still be effective. The detergent solution should be made fresh every time you clean the
burette, as it loses its potency quickly if stored as a liquid.
After you have run distilled water through your burette, close the stopcock, and fill with the
Burette Detergent solution. You can open and close the stopcock over a waste bucket or sink to allow
the solution to pass into the tip of the stopcock. We recommend letting this detergent solution sit in the
burette for one hour. Dispense the detergent solution then rinse the burette with distilled water twice
more. During this time we recommend opening and closing the stopcock to make sure the stopcock is
turning easily. If it is not, remove the stopcock and clean it thoroughly. Once drained, allow to hang dry
by hanging the burette upside down with the stopcock in the open position. Once the burette is dry, flip
it back over and cover the top opening with a piece of tape. This will prevent dust from getting in that
can cause aberrations when reading the burette. Remove the tape when you're ready to titrate.
Figure 8. The burette sits
firmly between the
notches of the four
spring arm knobs of the
Double Burette Clamp.
Figure 9. Use the end of
the Electrode Holder as a
guide for the glass burette
for accurate titrations.
Figure 10. The Pro Kit
Assembly is complete. Go
take some measurements!

SC-300 Pro Kit Manual 9 Version 2.2
Burette Reading
ALWAYS use eye protection and preferably gloves (latex or nitrile) when using glassware
and chemical reagents. To get the most accurate results when titrating, there are a few things to keep
in mind. We recommend reading from the bottom of the meniscus (Figure 12). First, use a thick sheet
of white paper, note card or the back of a business card and draw a black band down the center of the
paper about an inch and a half thick (Figure 11). When taking a measurement, hold the paper about an
inch behind the burette and the black band about a half an inch below the meniscus (Figure 13). This
provides a clear view of the bottom of the meniscus which helps make a precise, consistent
measurement. Second, when filling the burette, make sure the titrant (in most cases this will be either
the SO2Titrant or the TA Titrant) has completely filled the bottom of the burette including within the
tip. Sometimes bubbles can be trapped in the tip of the burette but can usually be dislodged by opening
and closing the stopcock while the burette is hovering over a waste container. We also recommend
washing a couple of milliliters of the titrant you are using through the burette to remove any excess
water or contaminants that may remain from a previous titration. Finally, make sure there are not any
large bubbles in the burette after filling. If there are, cover the top of the burette with some saran wrap
(or parafilm if you have it) and make sure the stopcock is in the closed position. Then take the burette
out of its clamp and hold the saran wrapped end tightly. Rotate and invert the burette to allow the
bubbles to move out of the column of titrant. Once the bubbles have been displaced, you are ready to
titrate.
Note: the gradations on your burette may be different than shown in the figures below. These photos
are of the 10 mL burette; the 25 mL burette will have fewer gradations. Please take a look at your
burette and determine the values for the gradations (lines).
Figure 11. On a thick white
sheet of paper or a business card,
use a black marker to draw a
band approximately an inch and
a half thick. This card will assist
you in reading the burette
accurately.
Figure 12. The meniscus of the
water column. We recommend
measuring the titrant volume
from the bottom of the
meniscus. In the picture the
value is about 3.27 mL.
Figure 13. Reading the meniscus of
the water column is easier and more
precise if you use the paper with the
black band held up an inch behind the
burette and its black band 1/2 an inch
below the meniscus. In this picture the
value from Figure 11 is further
resolved to 3.26 mL.

SC-300 Pro Kit Manual 10 Version 2.2
Before beginning the titration, record the starting titration volume, using the thick white paper
with the black band, and then begin titrating, slowly. With enough practice, you will eventually be able
to read the burette without black banded paper. Record the final titration volume using the same
technique. You can also checkout these websites for more burette info:
http://www.titrations.info/pipette-burette or http://www.csudh.edu/oliver/demos/buretuse/buretuse.htm
Instrument Operation:
1. Turn on the instrument by pressing the POWER button briefly (Note: depressing the POWER
button longer than two seconds at start-up will cause the instrument to enter Test Mode; see
Appendix A). The instrument will go through a power-up sequence. After a few seconds the
instrument will start in whatever mode was last selected. The mode is indicated by the yellow
LED panel on the left. Select the desired mode by pressing the MODE button.
2. SO2mode: This is for determining ppm of SO2 by titration (see below under ‘Procedures’) and
the SO2 electrode must be used. As a safety precaution, you must press the ENTER button after
selecting SO2mode to confirm that the SO2electrode is attached before the mode will be
enabled. However, scrolling through the MODE selections (such that you pass by the SO2
selection) with a pH electrode attached is safe, as long as you do not press ENTER to confirm
the SO2mode. After pressing ENTER, you should see the display show a value less than 50
(usually 0.0) and the green "PROCEED" LED should be on. Make sure to attach the SO2
electrode. Note: On older style, single connector units (pre-2014), the pH electrode can be
damaged by connecting it to the instrument in SO2 mode.
3. pH mode: In this mode, the meter measures the pH. The pH electrode must be attached. If the
instrument has not yet been calibrated, the message “doCal” scrolls across the screen, and you
need to do a calibration (see Calibration of pH below). We recommend re-calibrating the
instrument for pH once each day of use. Warning: Be careful not to press ENTER when the pH
electrode is attached while the instrument is in SO2mode, as this can potentially damage the pH
electrode. If this does happen, and the pH electrode does not respond correctly, place it into the
pH 4 Reference solution for an hour and it should return to normal function.
4. Potential mode (Firmware version 3.1.1 and higher) (pH LED flashing): In this mode the
instrument displays the potential in volts, (or millivolts in version 3.1.2 and above) coming
from an electrode attached to the pH connector. This can be used with certain electrodes, for
example, Vinmetrica’s Dissolved Oxygen System, ORP, potassium, or sodium electrodes, or to
view the raw voltage reading of a pH electrode. In this mode, when the red STOP LED is
illuminated, the values on the screen are negative; otherwise the values are positive.
5. TA mode: This is for titration in determining titratable acidity (TA). As in the pH mode, the pH
is displayed and the pH electrode must be attached. The green (“PROCEED”) LED is lit if the
pH is below the TA endpoint (normally 8.2, but can be set to 7.0, see Appendix A, Test Mode,