The Settings page displays the system information and settings Each block of settings is explained in the table below.

System information

This block contains system information, such as the serial number, hardware and software versions and systems (up)time. 


HostnameThe serial number of the spectrometer
Detector typeDescription of the scintillator crystal inside the spectrometer.
PSU VersionThe version of the Power Supply Unit (PSU) used in the system.
Carrier versionThe version of the microcontroller (carrier) used in the system.
mDOS versionThe version and release number of the medusa Detector Operating System (mDOS) running on the device.
System timeThe current system time of the spectrometer.
UptimeThe time the system has been switched on.

Sync time

Button to update the spectrometers time to the time of the device used to access this page.

Gamma Spectrometer

The gamma-ray spectrometer recording parameters can be adjusted here. The spectrometers are carefully calibrated and configured before leaving the Medusa office, and changing the settings should only be done if there is a good reason to adjust these parameters.


High voltage

The high voltage of the amplifier. The default value is unique for each detector.

Warning: Wrong high voltage or gain can lead to poor or incomplete spectra.

Note: The high voltage is shown if the detector contains a photomultiplier. If the detector contains a silicon photomultiplier, this option is replaced by the gain option.

GainThe gain voltage of the multichannel analyser. The default value is unique for each detector.
IntervalMeasurements per secondNormally 1 Hz is sufficient for all applications. Short intervals will cause the storage of the detector to be filled much faster.
Interval (ms)Custom measurement time
ChannelsNumber of channels in the measured spectrumThe default setting is 512 channels which are sufficient for most applications.

Spectrum inspection (optional)

Open a page in which the spectra of each individual crystal can be inspected.

This option is only present in spectrometer systems that contain multiple crystals.

Storage settings

Paused stateChoose how the detector will handle paused states:

Do not store paused state: When the system starts it will automatically start logging
Store paused state across reboots: The last known state is saved across reboots, e.g. when the system was paused when powered down it will remain paused when power cycled.
Always start in a paused state: The system will always start in paused mode and has to be unpaused by the user.

See the mDOS map block page for a description of the paused state.
Overwrite oldest files when fullWhen selected, the system will overwrite the oldest files on the system when no more storage space is available. Deleting old files goes on a project basis, meaning that when the detector is full, old projects will be deleted as a whole.
Signal when storage is filled (%)The percentage of storage filled when the SCN and AUX led will start blinking at in red to signal the device is almost full.
Storage graphA doughnut chart showing the amount of used and free space on the system

Spectral processing

The processing parameters that convert the measured multichannel spectrum to an energy spectrum and extract radionuclide concentrations. The processing methods are explained in the Gamman section.


Stabilization file
The currently selected calibration file used for stabilizing the raw spectraThis option is only available when using calibration files that have several anthropogenic radionuclides. 
Calibration fileThe currently selected calibration fileUpload MCF files can be inspected and deleted by using the blue info button. This will open a popup displaying the contents of the calibration file.
Active nuclideA list of radionuclides found in the selected calibration file. Here the nuclides used in the analysis can be (de)selected
Upload MCF fileUpload new MCF files
FitmodeMode to determine the concentrationsSee the fitting schemes page on the medusa institute page for an explanation of the modes and parameters.
Spectra to sumThe number of spectra to sum before analysing the accumulated spectrum.The live time of the measurement that is being analysed is the sum of this parameter and the live time set in the Gamma Spectrometer settings tab.
Show units

Output the concentration in Bq/kg or in % (potassium) or ppm (Thorium, Uranium). Cesium units are always presented in Bq/kg


These units are only used in the mDOS display. The data stored on the detector always uses Bq/kg

Conversions used:
1% 40K = 313 Bq/kg 40K
1ppm 238U = 12.4 Bq/kg 238U
1ppm 232Th = 4.1 Bq/kg 232Th

Dashboard unitsThe units that are shown on the dashboardCount rate or Dose rate. The dose rate represents the energy absorbed by the crystal and has the units of microGray per hour.  A dose rate according to the H*(10) standard can be calculated by reprocessing the data in Gamman. 

Spectrometer internals settings

This section is only visible if the spectrometer contains a wifi connection, an internal GPS or a PTH sensor.


Enable or disable the WiFi access point.

Note that when this option is turned off, the only option to reach the detector is by connecting to the spectrometer using a cable that has an ethernet connector. Not having the cable available means that the detector is inaccessible. Therefore, the only reason to change this setting is by clicking five times on the "Wifi:" before changing and saving the setting.
Internal GPSEnable or disable the internal GPS. Note that the system can log internal and external GPS at the same time. If the external GPS option is used, it is advised to disable the internal GPS
PTHEnable or disable the internal Pressure, Temperature and Humidity sensor

System Maintenance


UpdatesOpen the updates page to apply system updates or patches
Download logsDownloading the log files can contain system debug information. Medusa may request this download in case of detector issues.
Restore system defaultsReset the system to factory defaults. These settings that Medusa configured before shipping the system which unique for each system. Project data will not be deleted.

Map management


UnitsThe units used on the map viewer (metric or imperial)
Go online if availableIf enabled, the detector will try to download map tiles from the internet that function as a background on the map viewer. This can be disabled in the field or when using a mobile connection. 
Delete tilesOn the map viewer, offline maps can be downloaded. Offline maps are not connected to a project and can grow significantly in size when many offline maps are downloaded. Therefore it is possible to remove all stored maps from the detector.
SizeSize of the maps stored on the detector