A method of controlling a pulsed level gauge system comprising: transmission signal generating circuitry (10, 11) for generating an electromagnetic transmission signal (S T) in the form of a first pulse train having a first pulse repetition frequency; a propagation device connected to said transmission signal generating circuitry and arranged to propagate said electromagnetic transmission signal towards a surface of a product contained in a tank, and to return an electromagnetic reflection signal (S R) resulting from reflection of said electromagnetic transmission signal at said surface of the product; reference signal generating circuitry (14, 15) for generating an electromagnetic reference signal (S REF) in the form of a second pulse train having a second pulse repetition frequency; and processing circuitry for determining a filling level of said product based on said electromagnetic reflection signal (S R), said electromagnetic reference signal (S REF) and a known frequency difference (Δf) between said first pulse repetition frequency and said second pulse repetition frequency, characterized in that the method comprises the steps of: acquiring a signal indicative of a present operating temperature (T present); determining an initial frequency control parameter (V initial) for control of at least one of said transmission signal generating circuitry and said reference signal generating circuitry based on said present operating temperature and a plurality of data sets each comprising data indicative of a previous operating temperature and a previously determined frequency control parameter for said previous operating temperature; and controlling, starting from said initial frequency control parameter, at least one of said transmission signal generating circuitry and said reference signal generating circuitry to achieve said known frequency difference between said first pulse repetition frequency and said second pulse repetition frequency at the present operating temperature. transmission signal generating circuitry (10, 11) for generating an electromagnetic transmission signal (S T) in the form of a first pulse train having a first pulse repetition frequency; a propagation device connected to said transmission signal generating circuitry and arranged to propagate said electromagnetic transmission signal towards a surface of a product contained in a tank, and to return an electromagnetic reflection signal (S R) resulting from reflection of said electromagnetic transmission signal at said surface of the product; reference signal generating circuitry (14, 15) for generating an electromagnetic reference signal (S REF) in the form of a second pulse train having a second pulse repetition frequency; and processing circuitry for determining a filling level of said product based on said electromagnetic reflection signal (S R), said electromagnetic reference signal (S REF) and a known frequency difference (Δf) between said first pulse repetition frequency and said second pulse repetition frequency, acquiring a signal indicative of a present operating temperature (T present); determining an initial frequency control parameter (V initial) for control of at least one of said transmission signal generating circuitry and said reference signal generating circuitry based on said present operating temperature and a plurality of data sets each comprising data indicative of a previous operating temperature and a previously determined frequency control parameter for said previous operating temperature; and controlling, starting from said initial frequency control parameter, at least one of said transmission signal generating circuitry and said reference signal generating circuitry to achieve said known frequency difference between said first pulse repetition frequency and said second pulse repetition frequency at the present operating temperature.