RadioactivityCounter vs Low Frequency Detector

RadioactivityCounter This application is a real working radioactivity counter without any extra hardware needed ! It will turn your phone into a Geiger Müller Counter to measure radioactivity after proper calibration. ** Attention after upgrading iOS to a higher iOS do the calibrate again, as camera data properties might have changed ** Disclaimer: The type of radiation picked up by the camera can be dangerous/detrimental to the user's health as well as cause damage to the device. Important note: The camera sensor can measure gamma radiation (CS137 for example) and some beta radiation (depends on the energy if the beta rays can pass through the plastic parts - for example H3 or K14 are weak sources). It cannot measure alpha rays (PO210) For AM241 though its primary a Alpha source also some gamma radiation is emitted and might be detectable for a longer measurement. Please check our homepages for examples and hints on how to measure. We did calibrations with several iPod2*, IPhone 3GS*, iPhone 4*, iPhone 4S, iPhone5, iPhone 5S iPhone 6, 6s and iPad 2, iPad 3* devices at the Helmholtz Research Centre, Munich. we used a CS137 test source from 10 µGy/h till 1 Sv/h for each of the phones we had. The values are stored for a rough start on the application (all devices differ a little bit). For precise professional measurement the devices must be adjusted to the sensor which is possible with the expert setup. For personal use the defaults should be sufficient (please give us feedback). * = Attention some phone might not be compatible due the new version of iOS or missing features (gps precision using sim cards)- please try to use an older rev of the App which should be available according to my settings (1.3).

"Low Frequency Detector" is an acoustic measurement tool for detecting low-frequency sounds that is hard to hear in normal situation. The human ear is not sensitive enough to low-frequency sounds. If you are exposed to noise from nearby construction or factories without realizing it, you may feel discomfort or a sense of pressure. In such cases, you can use this app to check what kind of low-frequency noise is present. Generally, low-frequency sounds is a sound wave ranging from 1Hz to 100Hz. Depending on its frequency component and sound level, the degree of influence on the human body and the noise sensation is different. This app allows you to examine the frequency component of low-frequency sounds by 1/3 octave band analysis and FFT analysis. Features: - Low-frequency power level measurement less than 100Hz (LF Level): Flat characteristic, Updating indication of measurement period 1 sec. - Power level measurement in the audible band (Leq): Flat characteristic, Updating indication of measurement period 200ms. - 1/3 octave band analysis (OCT) - FFT analysis (FFT) - Time course graph (TIME) - Snapshot (Snap) on the measurement display screen. - Report function (Report): Analysis report of a peak LF Level with TIME, OCT and FFT. - Measurement time: up to 60 sec Functions: The measurement analysis is performed in the following step. Be sure to set the measurement conditions in Step-1 once before starting the sound measurement. 1) Calibration (Calibrate): The reference signal (1kHz sine wave) is output to determine the reference noise level for the low-frequency component. If the volume level of iPhone is set to about 20-50%, the calibration will automatically adjust it to the optimum volume level for the reference signal. 2) Measurement (Measure): Analyze a power level of low-frequency sounds. - LF Level (dB): Low-frequency power level less than 100Hz. - Leq (dB): Sound power level with the frequency weight characteristic Z (Flat) of the audible band. 3) Measurement display: It can select either 1/3 octave band frequency analysis, FFT analysis or Time course graph. They are updated in real time. 4) Report: Measurement result report. It is effective when measuring for 10 seconds or more. # Time course graph: TIME - Low-frequency (LF) Level (dB): Time course graph with peak level noise level judgment (RED-very noisy, YELLOW-noisy, GREEN-normal) at the peak level. - LF max (dB): maximum dB value of low frequency. # Frequency response graph: OCT, FFT - OCT Band LF max (dB): maximum dB value in 1/3 octave band at LF max observation. - Max Level Frequency (Hz): peak frequency at LF max observation. Notes: - The sound measurement of the low-frequency range is a level difference with respect to the reference signal, which indicates the relative power level. - The reference signal is output during calibration and sound level measurement. - Do not change the volume level of iPhone after the calibration. - White line in the OCT and FFT modes indicates frequency characteristics in frequency weight correction of G characteristics. - Since iPhone's built-in microphone has a lower sensitivity on the very low frequency range, it is not recommended to measure a huge volume sound near a very loud noise source. - Since it takes a while for the observation value to stabilize immediately after the start of measurement, the maximum value is calculated from about 2 seconds later. - In the case high power of 1kHz component is included in the measured noise source, the precision of measured value by this app largely decreases. - Sudden noise or impulsive sounds are not low frequency noises in general. - The previous calibration information can be maintained internally. - The analysis results may vary due to individual differences in iPhone devices. - The authorization to access built-in microphone and Photos will be confirmed by iOS system at first access. Please visit our iOS app support page for more information.