How to use a bolometer to measure power?

hello,
does anyone know how exactly a bolometer is used? I mean how can I use a bolometer to measure power? Do I need a bolometer bridge and how must I use it?

It seems there are not much information about bolometers used in microwaves on the web...

Thank you

Bolometers are usually incorporated into power meters and you don't have to really worry too much on the details. This is especially true with the advent of low cost USB power meters.

Basically any situation where you'd want to measure microwave power, you'd use one. It's basically a load termination combined with a thermocouple or RTD temperature sensor.

It happens to have an old bolometer and a bolometer bridge available so I would like to try this way.

I did not know that they are still used in these usb power sensors... I thought there had to be a way of measuring power using a superhet-like front end.

Bolometers are wire resistors which change resistance when hit by electromagnetic power coming at microwaves, IR, etc.

The best way to use them is to install two bolometers into a Wien bridge. One bolometer is left enclosed so that no irradiation is coming to it; the other bolometer is irradiated. Then the output voltage of the Wien bridge will change in proportion with the irradiation intensity.

Most often, bolometers react to low power levels of irradiation, and DC amplifiers are used to measure the bridge output voltage. For the highest sensitivity, bolometers are (the complete enclosure) cooled in liquid nitrogen or hydrogen.

I saw somewhere a newspaper article describing how Edison used a bolometer bridge with a small telescope to demonstrate detection of light intensity from a star.