Measuring Fish with Torrymeter

Measurement Procedures

Once you have set up the various menu options to suit your requirements, you can then proceed to take measurements.

Have a copy of the organoleptic charts at hand, and pen and paper to note results. Alternatively you can download the data from the Meter on completion of sampling. For best accuracy, always follow the measurement recommendations in your Handbook / Measurement Chart.

Here is a quick check routine…

  1. You have set the correct number of samples: Choice from 1 to 16, from Samples menu.
  2. You have selected the correct calibration setting on meter for the fish being sampled.
  3. If correct calibration for the fish species being measured is not available in your meter, check to ensure that you have prepared or have been supplied with an Organoleptic Chart suitable for this fish species.
  4. Select the fish samples at random from the batch. Where you are taking fish samples from a varied batch, the samples should be grouped according to size (length / weight).
  5. Temperature of the fish to be measured should be between 0 – 10oC, with no ice crystals present in the samples.
  6. Ensure that the sensor is placed firmly against the skin of the fish, thus ensuring that there are no air pockets between the sensor and the sample to be measured. Press the READ button; the Meter will confirm contact with the fish, take the measurement, display and store the value.
  7. For best results…BE CONSISTENT. Always place the sensor on the same part of the fish, day-to-day. This will ensure that you achieve optimum, comparable results. It is normal to experience variability in the individual readings when taken at different parts of the fish. (Please note that different parts of the fish will spoil at different rates, depending upon the level of bacteriological activity present within the fish)
  8. ONE reading should be taken from each fish, at recommended measurement sites. The results will be stored in the Meter for later downloading.
  9. Place the base of the meter firmly on the fish so that it lies flat against the surface and parallel to the lateral line at a thick, fleshy part of the fish. The best position is at the shoulder area within the first third of the fish, in the region of the lateral line. Avoid the head and belly cavity regions (see illustration).
  10. If this is the first reading after the meter has been in a warm place, hold the probe head against the fish for 10-20 seconds, to allow the sensor to cool down before pressing the READ button.
  11. Note the reading, then press the RESET button, and go on to the next batch of fish.
  12. To measure individual fish, set samples = 3, place meter at recommended measurement site, and take measurements three times. The individual values + average value will be stored in memory for downloading. Press the RESET button before going on to the next fish.
  13. Avoid pressing the READ button when the meter is not in contact with a fish. If there is a thick layer of slime on the probe head it may conduct enough current to act as if the electrodes were in contact with a fish and a measurement will be made.
  14. Switch OFF after use to preserve battery charge.