Device for determining a gas mass flow rate, and method for re-calibrating such a device

A device for determining a gas mass flow rate, the device comprising:

• a first sensor unit comprising at least one first temperature measuring element and a first heating element;
• a second senor unit comprising at least one second temperature measuring element and a second heating element;
• and
• a control unit configured to adjust the first heating element to a first controlled excessive temperature, the control unit being connected to the second heating element so that the second heating element is adjustable to a second controlled excessive temperature.

A method for recalibrating a device for determining a gas mass flow rate, the device comprising:

• a first sensor unit comprising at least one first temperature measuring element and a first heating element;
• a second senor unit comprising at least one second temperature measuring element and a second heating element;
• and
• a control unit comprising a stored correcting table
• the method comprising:
• adjusting the first heating element to a first controlled excessive temperature;
• calculating a first mass flow rate from a heat dissipation of the first heating element in dependence on a temperature of the at least one second temperature measuring element;
• storing the first mass flow rate determined if a controlled stationary engine condition is detected;
• switching over the control unit;
• adjusting the second heating element to a second controlled excessive temperature;
• calculating a second mass flow rate from a heat dissipation of the second heating element in dependence on a temperature of the at least one first temperature measuring element;
• comparing the first mass flow rate with the second mass flow rate;
• and
• recalibrating the first sensor unit based on the correction table.