If ingested, Beta radiation can be hazardous to living tissue. These particles are relatively light and can penetrate somewhat better than an Alpha particle, though still only through a few millimeters of aluminium at best. A weak form of ionizing radiation detectable on some models of Geiger counters, typically those that incorporate a thin mica window at one end of the Geiger -Mueller tube.īeta radiation consists of negatively charged (-1) particles emitted from an atom in the process of decay. Because of this, Alpha particles are not a serious health hazard, except when they are emitted from within the body as a result of ingestion, for instance, when their high energy poses an extreme hazard to sensitive living tissue. These particles are also very dense which, with their strong positive charge, precludes them from penetrating more than an inch of air or a sheet of paper. This results in a short, intense pulse of current which passes (or cascades) from the negative electrode to the positive electrode and is measured or counted.Īlpha radiation consists of positively (+2) charged particles emitted from the nucleus of an atom in the process of decay. The ion pairs gain sufficient energy to ionize further gas molecules through collisions on the way, creating an avalanche of charged particles. The strong electric field created by the tube’s electrodes accelerates the ions towards the cathode and the electrons towards the anode. When ionizing radiation passes through the tube, some of the gas molecules are ionized, creating positively charged ions, and electrons. The walls of the tube are either entirely metal or have their inside surface coated with a conductor to form the cathode while the anode is a wire passing up the center of the tube. The tube contains electrodes, between which there is a potential difference of several hundred volts (~500V), but no current flowing. The Geiger TubeĪ Geiger–Müller tube consists of a tube filled with a low-pressure (~0.1 Atm) inert gas such as helium, neon or argon (usually neon), in some cases in a Penning mixture, and an organic vapor or a halogen gas. The pulses can be counted using the interruption on digital pin 2. If the board is connected to Raspberry Pi, the power is taken from the 5V pin. The board is connected to Raspberry Pi through the Raspberry Pi to Arduino Shield Connection Bridge
#Beancounter raspberry pi series#
These leds are connected to digital pins of the microconroller with a series resistor.Ĭonnecting the Radiation board to Raspberry Pi The LED bar is made with five standard LEDs, 3 green and 2 red. The LCD screen is connected to the microcontroller using the 4-bit mode (4 data lines in addition to RS, Enable and RW control lines). The piezo speaker and LED indicator are connected to the adaptation circuit, so the LED will blink with each pulse and the speaker will sound with each pulse. The adaptation circuit for the output is based on a NPN transistor, this transistor will trigger the interrupt pin in the microcontroller, this transistor is also activating/deactivating the piezo speaker and LED indicator generating the audio/visual signal.
#Beancounter raspberry pi code#
The code we use for the board is counting pulses for 10 seconds, then we multiply the number of pulses by 6, so we get the number of pulses by minute (cpm), then, according to the tubes documentation we divide cpm by the conversion factor of the tube (360 by default) and we have the value of radiation in µSV/h.ĭepending on the tube you use, maybe you need to change the calculation, you should try with different values and comment us witch value is working better. Once the tube is powered, we can receive the pulses in the microcontroller and count them, then with an easy calculation we can get the value of radiation. The power part is used to provide the voltage necessary for the tube ( 400V – 1000V) and the signal circuit is used to adapt the pulses output from the tube and connect it to the input of the microcontroller. The radiation board has two main parts, the power circuit and the signal circuit.
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