Abstract: An electrochemical sensor is disclosed, including an electrode disposed on a first ceramic insulation layer, a porous electrolyte stabilization layer disposed around and on top of the electrode, a conductive ceramic substrate in contact with the first ceramic insulation layer on a first side, a second ceramic insulation layer in contact with the conductive ceramic substrate on a second side, and an integrated heater in contact with the second ceramic insulation layer. A telemetric electrochemical sensor system and a method of sensing gaseous analytes is disclosed, which includes exposing a gaseous mixture sample to a hydrogen separation membrane disposed on top of a porous electrolyte which may include an iron (Fe) doped barium niobate perovskite, establishing a first mixed potential at a first electrode, establishing a second mixed potential at a second electrode, and determining a voltage difference as a sensing parameter to be measured.