Gas Sensor Test System

Overview
Because our lab did not have any closed, heated chamber that could be evacuated and also allow electrical connections to the sensors, I designed and built a simple gas sensor test system. It provides a sealed stainless-steel chamber with heating, basic vacuum capability, and electrical feedthroughs for connecting sensors to an external multimeter.

1. Defining the need

We needed a setup that could:

Enclose gas sensors in a sealed chamber
Apply controlled heating to the sensors
Allow vacuum or controlled gas flow
Bring electrical leads out of the chamber to measure sensor resistance with a multimeter.

2. Designing the stainless-steel test chamber

I designed a cylindrical stainless-steel vessel as the main test chamber:

Stainless steel was selected for chemical resistance and durability.
A removable lid with a sealing gasket was used to ensure leak-tight operation.
Several toggle clamps were added around the lid to provide uniform sealing pressure and quick opening/closing.

3. Integrating heating

Inside the chamber, I installed an electric heater under the sensor stage so that the gas sensor could be heated up to the desired test temperature.
The heater temperature is controlled from the front panel using a digital temperature controller.

4. Vacuum and gas connections

To allow evacuation and gas introduction:

I added a side port with a valve that can be connected either to a vacuum pump or to a gas line.
This made it possible to test sensors under low pressure or in a defined gas environment.

5. Electrical feedthroughs and front panel

Since we needed to measure sensor resistance during testing:

I designed electrical feedthroughs from the inside of the chamber to the front panel.
On the front panel, I installed banana connectors so that a multimeter or external measurement system could be easily connected.
A digital temperature display and a main power switch were also mounted on the front panel.

6. Assembly and use

After assembling the chamber, heater, valves, and electrical connections on top of a metal box:

I tested the system for leaks and temperature control.
The setup was then used to characterize gas sensors by applying heat and specific gas conditions while monitoring their electrical response

Gas Sensor test system