Patent ID: 7174768

Claim:
A hydrogen sensor comprising: a hydrogen-absorbing material; a thermoelectric element that transfers heat to and from the hydrogen-absorbing material; an electrical circuit configured to drive the thermoelectric element and to cool the hydrogen-absorbing material; a thermometer configured to determine a temperature of the hydrogen-absorbing material; a temperature control circuit for maintaining the hydrogen-absorbing material at a constant temperature which has a same temperature as an ambient temperature without heat transfer with a gas to be sensed by controlling electrical current flowing to the thermoelectric element; a unit for calculating the exothermic value of the hydrogen-absorbing material based on variations in the electrical current flowing from the drive circuit by determining a cooling heat value which the thermoelectric element requires to cool the hydrogen-absorbing material, the exothermic value having a same value as the cooling heat value; and a unit for calculating the hydrogen uptake of the hydrogen-absorbing material based on the exothermic value.