A magnetometer comprising: a sensor formed of diamond material and comprising a plurality of spin centers; a microwave source configured to subject the plurality of spin centers to microwave pulses; a light source configured to subject the plurality of spin centers to light pulses; and a detector configured to detect a fluorescent output signal emitted from the plurality of spin centers, wherein the magnetometer is configured to integrate the fluorescent output signal over a signal averaging time and process the fluorescent output signal such that a standard deviation of the fluorescent output signal decreases with the square root of the signal averaging time over a time period which spans at least two orders of magnitude in the signal averaging time to achieve a standard deviation of less than 100 picotesla.