Testing Food (6 posts)

  • Profile picture of admin admin said 2 years, 8 months ago:

    You cannot simply point a geiger counter at a plate of food and expect to find anything, you really need a lab to test with far more sensitive equipment and procedures.
    Fellow longterm expat, Allan, has been determined to find a way to do this cheapily. Will post some info soon on his progress.

  • Profile picture of allan allan said 2 years, 8 months ago:

    Here is the result of 4 calibration runs with the pancake tubes in the lead
    shield with lid on – each at 1 hour.
    run 1: 2256 counts
    run 2: 2262 counts
    run 3: 2152 counts
    run 4: 2184 counts

    Run 1 and 2 were done late last night, and runs 3 and 4 were taken this
    morning.
    I wonder if it is just a coincidence that the daytime readings are lower
    than night time?
    It may be looking like we need to go for a measurement time longer than one
    hour.

  • Profile picture of allan allan said 2 years, 8 months ago:

    A collegue just emailed me furhter comments on this.
    “Cosmic radiation has a diurnal cycle, but it isn’t completely in phase with sunlight. The magnetic field of the earth bends many of the rays (but not sunlight) so the daily peak is in the shifted. How much and in which direction depends on where you are in relation to the magnetic poles.

    Then there is “space weather”. The flux of particles in earth’s vicinity is quite variable. See here: ( http://www.swpc.noaa.gov/today.html ) or here: ( http://spaceweather.com/ ) for recent levels and forecasts.

    The usual procedure is to do calibration runs before and after the sample (or at the beginning and ending of the day for an eight-hour lab shift) and average the two for background subtraction from the test counts.”

  • Profile picture of allan allan said 2 years, 7 months ago:

    Just processing some food for testing
    Hakusai (Motomiyashi)
    White Rice (Motomiyashi)
    Moyashi (from Nigata )
    Shitake (Iwaki shi)

    Drying the Shitake in the oven, house stinks!

  • Profile picture of lentildude lentildude said 2 years, 7 months ago:

    Your mushroom results will be interesting.
    The govt limit is 500 becquerels per kilogram which seems very high to me.

    “The Fukushima prefectural government says 1,770 becquerels per kilogram of radioactive cesium was detected in mushrooms grown in Date City. The level is more than 3 times the provisional government limit of 500 becquerels per kilogram.”

  • Profile picture of allan allan said 2 years, 7 months ago:

    Am waiting on a shipment of contaminated Fukushima rice that has been lab tested. Will test in the home setup.

    Now testing some Kombu from local supermarket that is suspect. Just waving the geigercounter over the packet gave a reading.