NOTE: Before starting any measurements, ensure the camera lens is covered! The easiest way to do this is with a couple of strips of electrical tape.
- Note that the quick start section is for quick and general use. More advanced and professionally preferred settings are capable and available through the Noise removing, and settings sections.
- Removing Camera Noise : If the app has not been previously removed noises, press the "Remove Camera Noise" button. For more information about the noise removing please see camera noise removing.
- Measure: If you have a particular object you want to measure face the camera toward that object and press measure. It sometimes takes a few seconds for the phone to start measuring, this is normal. you can stop reset the counts and re-measure again. If you want to measure in background you need to enable the background mode in the setting.
- Beeping sound: Each beep represents a count detected by the phone. You can disable this in the settings page. Registering only occasional, or sometimes no counts is normal. This just means your environment is safe.
- Alarm: Your phone will alarm if it detects more counts than the alarm threshold. The alarm is disabled by default and users can enable the alarm and set their own thresholds as desired. The default threshold is set to engage the alarm when counts over 50 Cnts/1000F are registered.
- Reading Data: Measured counts are displayed on your screen. You can save data to your phone memory if desired, see data logging in the Settings menu.
- Stop measuring: Stop measuring by pressing "STOP" button. Pressing the back button won't stop measuring if background mode is enabled and the app will continue to measure in the background
- Exit app: Exit the app by opening the menu button on top left corner and close the app, This will stop all measuring and will exit the app.
During the noise removing process, the app finds the brightness threshold and identifies noisy pixels and excludes them from analysis.
If your device has not been previously removed camera noises, the “Measure” button on the home screen will be greyed out till you remove camera noises once. Dont press the measure button while removing noises. your device is still removing noises if "Finding Noise Signature" is displaying on top of the screen. It will also show the noise threshold which should be in the range of 14 – 60. If it is over 60 please use other modes (see setting section for changing modes) and try noise removing again or contact us at firstname.lastname@example.org.
Removing Camera Noise takes a few minutes, but once this is done the parameters will be remembered and you won’t have to repeat this step. However, you can re-removing noise at any time. For example, you may want to re-removing camera noise if you find that the app is detecting radiation, even when you are in a low radiation area. (This could happen if you did the initial removing noise when the phone was cold but you are using it after it has warmed up.)
- Finding Conversion Factor
For more accurate measurements when using units other than [Counts], you can enter the [Cnts/1000F] to [uSv/h] conversion factor into the setting (see setting page for more information). This factor is set to 1 by default and varies from phone to phone. In order to find the conversion factor, expose GammaGuard to a known radiation level and record the dose rate in Cnts/1000 frames (either directly from the "Dose Rate" display, if you have a strong field, or by multiplying the "Total Cnts/Total Fr" by 1000. Then, divide that value by the known dose rate, in uSv/h. This value typically ranges from 0.3 to 3. (You can find this factor by measuring the radiation from an ordinary smoke detector ).
- Optimize your phones performance
You can improve the performance of your phone by finding the optimized configuration of your camera settings. Please click here to see the procedure and example of how to find the optimized mode of your phone.
- The top header displays the current operation mode of the application. You will either be in removing noise mode, measuring mode or idle mode (not counting). You might see either of these top headers :
- Idle:Power Save/Idle: High Sensitivity Indicates the device is not actively detecting radiation (counting) or updating count values. Also shows which measurement mode (Power Save or High Sensitivity) is currently selected.
- Measuring: Power Save/Measuring: High Sensitivity Indicates the device is measuring radiation and displaying counts on the home screen as radiation events are detected. Also shows which measurement mode (Power Save or High Sensitivity) is currently selected.
- Removing Camera Noise: Finding Noise signature Device is currently removing camera noise and finding noise signatures of your phone.
- Shows if the app is removed camera noises or not. It will also show the noise threshold.
- Frame rate, or number of frames which are getting analyzed per second. This tells you how fast your phone is analyzing the frames during measurements.
- You will either be using the front camera of the phone or the back camera. This will display the one that is currently being used. (Remember to cover the camera you are using.)
- The four lines of data in the home screen are:
- CamCounts : Shows the number of immediate counts as detected by the camera.
- Dose[units] : Shows the accumulated dose. if no units has been selected, it shows the number of total Cnts times Hour per 1000 frames.
- Dose rate [units] : Shows the 2 minute average dose-rate. If no units have been selected, it shows the 2 minute average of counts detected per 1000 frames.
- Total Cnts / total Fr : Shows the number of total counts, total number of frames and total counts per total frames.
The following settings are user-adjustable in settings page:
- Dose Rate Alarm: This is the Dose rate level to be exceeded before an alarm is sounded. The alarm will sound even when the app is in the background.
- Display units: Changes the display units from counts to Sv or Rem.
- Command Line: Is used by expert users to adjust various additional parameters, affecting program execution. The general format is a lower case letter followed by an integer:
- (t) Manual Threshold: This overrides the brightness threshold found by the noise removing process. For example, t34 would set the threshold to 34.
- (f) Conversion Factor: Converting Count unit to Sv and Rem would depend on calibration and would vary from camera to camera and from phone to phone, this conversion factor can be changed by entering lowercase letter "f" followed by a number. To see how to find a conversion factor for your phone , please see our look at our smoke detector example.
- (m) Camera parameter modes: This command sets the different modes for camera parameters. Parameters are [ ISO, Exposure-compensation, scene-mode, whitebalance, flashmode, focusmode, antibonding ] Enter the letter m followed by a number between 1 to 4 (e.g. m2 sets the mode to mode "2"). Use : (m1) for enabling all parameters, (m2) [default mode] for enabling all parameters except the "scene mode" (m3) for enabling all parameters except the "scene mode" & "Exposure Compensation" and (m4) restore all parameters to phones default. to see examples and results of different modes in different phones click here.
- (e) Camera exposure compensation: This command sets the exposure compensation, which adjusts exposure to light. The typical range is -4 to +4. A lower number allows less light through to the camera. Enter the letter e followed by a number between -4 and +4 (e.g. e0 sets the exposure compensation to 0).
- (s) Camera ISO This command sets the ISO, which adjusts the sensitivity of the camera to light. Valid values for the most cameras are [auto,100,200,400,800]. For some phones this needs to be entered as [ISO100, ISO200, ISO400, ISO800]. Some cameras can be set as high as 1600 or 3200. Note that entering an invalid value could cause the app to crash. Enter the letter s followed by a valid value (e.g. s100 sets the ISO to 100).
- (l) Log out "Measurement Histogram" This command sets the logging of a measurement histogram ON or OFF. If it is set to ON, it will log the histogram of every frame. Note that this uses a large amount of memory, and should therefore be turned OFF when not needed. Enter the letter l followed by "ON" or "OFF" (e.g. lON turns on histogram logging).
- (c) Camera Uncovered Warning Threshold: This command sets the percentage of bright pixels that will trigger a warning stating the camera is uncovered. Enter the letter c followed by the percentage (e.g. c50 sets the percentage to 50%).
- (p) Measurement period: Number of Seconds per measurements cycle. Enter the letter p followed by the integer (e.g. p15 sets the measurement period to 15 seconds). The number of frames measured in each cycle is "p x 10".
- (i) Logging Intervals: Logging data time intervals in Seconds. Enter the letter i followed by the integer (e.g. i10 sets the interval time to 10 seconds).
- (r) Camera Frame Rate: This command sets the frame rate in Frame Per Seconds (FPS). Enter the letter r followed by the number (e.g. r10 sets the FPS to 10). some cameras only accept values within their supported range, to get supported range enter "r0" in command line. ("r0" also sets the FPS to its default)
- (o) Delete internal memory text files: This command can delete any logged data which has been stored into the phone memory. "o1" delete noise removing data. "o2" delete histogram data. "o3" delete camera_logged data. "o0" delete all stored data.
- (n) Number of first noisy frames to through out: This command will change the number of noisy frames that app through out at beginning of measurements. Default value for this is 8. (e.g. n10 sets the number of thorough out frames to 10 seconds).
- Other commands will be added as required.
- Command Line for External Detectors:
- (d) Compensation Factor: This change the external detector compensation factor. For example, d0.6 would set the compensation factor to (0.6), and it will change the factor of any detector which will be connected to the app to (0.6). (the default factor is 1)
- (CT007) CT007/AM003 detector Enable/Disable : This can Enable/Disable the CT007 detector page. This command should be entered in the settings page of the External Detector. It can be changed by entering "CT007" followed by "ON" or "OFF". For example "CT007ON" will Enable the CT007 page and the button to navigate to this page will be appeared on the External detector page. (default is disable for this command). To see the external detectors that can be connected to the Gammaguard app click here.
- Sound: Toggle this setting to enable/disable beeps to notify when a count is detected.
- Alarm: Toggle this setting to enable/disable alarm warnings.
- Data Logging: Enable data logging to have count information logged with timestamps to a text file on your phone's SD card. Data logging can be done either manually by pressing "Log Data" button or automatically every 5 min (default). You can change the default logging time intervals in command line.
- Total Counts: Press Reset to clear the current total number of counts.
- Front Camera: Toggle this setting to enable/disable the front camera (disable/enable the rear camera) for measurements and camera noise removing. The front camera on some phones is very noisy. Using the back camera usually gives better results.
- Power Save: Enable power save mode to save battery life while the app is measuring in the background.
- External Detector Mode: Enable this mode to enable the external detectors button on the home page. You can use that button to go to the external detector page and connect an external detector to the app via bluetooth.
- Uncovered Warning: The app stops the measurements and warns the user if the camera is uncovered. Disable this if you don't want the app to warn you about the uncovered camera.
- About: Tap this button to see the app version and firmware information.
- Save Settings: To save any changes made to settings, press this button before returning to the home screen.