"Nernst” – Say What?

“Nernst” – Say What?

Does your truck have a “Nernst” sensor — or just need a tissue? Despite the funny sounding word, chances are that your truck does have a Nernst sensor. No tissue required!

Some manufacturers use this term to refer to an oxygen sensor. You may have also heard the term “Lambda” sensor. This is another nomenclature for an oxygen sensor.

Image from the Walther Nernst memorial website

So, why is it called Nernst? In 1897, a German scientist named Walther Nernst developed a lamp that used a zirconium oxide – yttrium oxide ceramic electrolyte. The same type of material that was used in this lamp is now used in oxygen sensors in three-way catalyst systems. This ceramic material is found at the core of an oxygen sensor. As exhaust gas passes over the exterior of the ceramic core, a reduction reaction occurs, generating a signal voltage based on the relative oxygen content of the exhaust gas.

Accurate readings from your truck’s oxygen sensors — no matter what you call them — are integral to the correct operation of the emissions system.

You can learn more on the Walther Nernst memorial website: https://www.nernst.de/lambda/lambda-sensor.htm