Operation

For more tutorials visit the Rare Combinations YouTube channel!


Operation Instructions:

WARNINGS

  • NEVER allow foam or liquid to enter the detector. ALWAYS use a drop of antifoam or ~1 mL of oil in each kombucha sample.
  • Measuring a sample slightly reduces alcohol content. Use a fresh sample for each measurement to ensure accurate results.
  • Sample tubes are not meant for measuring; it is best to use a graduated cylinder and/or pipette when measurements are needed.
  • Accuracy of about +/- 0.05% is expected if the temperature calibration procedure is followed.
  • This product is designed to be a spot-checking device in day-to-day operations and should not be a replacement for GC-FID lab testing.
Sample Preparation
  1. Prepare a blank sample tube.
    • Label a sample tube “air” and set aside.
  2. Prepare a rinse sample tube.
    • Label a sample tube “water” and fill with water between the 20mL and 30mL line.
  3. Prepare samples.
    • If necessary, accurately dilute your sample so that the reading will fall between the calibration range of the detector (0.1%-2.0%).
    • Fill a sample tube with your sample to about the 20mL line.
    • Keep track of or label your samples.
    • Place a cap on all samples until ready to measure.
    • Ensure the samples are at the appropriate calibration temperature.
  4. To prevent foaming add about 1 mL of a neutral oil like vegetable oil to each sample; this will greatly reduce foaming. A drop of an antifoam product has also been shown to work very well.
Temperature Calibration (Video Tutorial)

       It is very important for the alcohol detector to be properly calibrated.  The idea is to use a 0.5% known sample and change the sample temperature until the display reads 0.50%.  However, as mentioned in the standard operating procedure, taking the reading of a sample can reduce the alcohol concentration of the sample.  Samples can be cooled by placing briefly in a refrigerator, freezer, or ice bath and they can be warmed either by being left out at room temperature, placed in a hot water bath, or warmed in the user’s hands.  A thermometer is now built into the alcohol detector but having a separate one is helpful.

  1. Prepare a sample tube with about 15 mL of 0.5% alcohol diluted in water (~50 mL of this will be provided with your detector).
    • To make more 0.5% standard: mix 5 mL of 95% grain alcohol with 945 mL of water. It is recommended to make a large quantity to reduce measuring error.  Store in a refrigerator.
  2. Follow the standard operating procedure below to measure the alcohol of the prepared sample (no oil or anti-foam is required for water-alcohol standards).
  3. If the reading of the detector is 0.50%, then your detector is calibrated at the temperature you recorded.
  4. If the reading of the detector is lower than 0.50%, then prepare another warmer sample and repeat steps 1, 2, and 3; if the reading is higher, cool the new sample and repeat steps 1, 2, and 3.
  5. Continue making new samples, heating/cooling them, measuring the temperature, and then taking the reading until the detector reads 0.50%.
  6. Use this temperature for all unknown samples; temperature calibration should be checked every use for the most accurate results.
Standard Operating Procedure for Measuring Samples
  1. Plug in the detector.
  2. Screw in the tube labeled “air”.
  3. Turn on the detector using the on/off switch. Buzzing should be heard from the detector and the display should turn on.
  4. Wait for the sensor to warm up (about 15 minutes); the display should read 0% after the 15 minutes.
  5. Check that the sample temperature is at the calibrated temperature.
  6. Keeping the detector upright, screw in the sample to be read.
  7. Watch the sample to ensure no foam is reaching the detector.
  8. Allow the reading to stabilize. This will take anywhere between 10 seconds to 2 minutes depending on the alcohol concentration and whether oil was used.
  9. Remove the sample from the detector.
  10. Wipe any excess liquid or oil from the down stem.
  11. Insert the tube labelled “water” and wait until the detector reads 0% again (this should take about 30 seconds to a minute). Remove the “water” tube.
  12. Repeat steps 5 through 11 until all samples are read; for best results, prepare two samples of each liquid to be tested and average the readings.
  13. Insert the “air” tube for about one minute before turning off the detector.
  14. Store the detector at room temperature and low humidity with no tube inserted.
  15. Wash and dry used tubes for the next use.
Notes on Improving Accuracy
  • Be sure that the sample tube is properly screwed in while taking readings.
  • Accurately measure the 0.5% alcohol standard.
  • For very accurate results, use the raw sensor reading to the right of the alcohol percentage to create a standard curve at whichever temperature you would like. Watch the video tutorial.