U-Value Measurement Instrument

Dear customer,

regarding several requests we decided to put an extra website
online, which concentrates only on U-value measurements.
Just click on the following link:


What is a U-Value?

In the field of building physics, U-Value is the term used to describe the heat transfer coefficient of a building element (e.g. of a wall). The U-Value describes the insulation quality of a building. The unit of the U-Value is W/(m2K). The smaller the U-Value, the better the insulation quality of the building element.

How do I get the U-Value of a building element?

Today, the U-Value of a building element is determined using one of these four approaches:

  1. Heat Flux Method or U-Value Measurement
    This approach uses a Heat Flux Sensor and two temperature sensors. This approach is standardized in ISO 9869, ASTM C1046 and ASTM C1155. This is the only method which delivers reliable quantitative in-situ information about a building envelope.
  2. Thermography (i.e. Infrared Imaging)
    This approach shows the thermal radiation of an object and produces an image showing spots with higher and lower radiation. It does not produce a U-Value, it just produces an image.
  3. Multiple Temperature Measurements
    This approach is based on three or more temperature measurements on both inside and outside of a building element. While this approach produces a U-Value, it needs a minimum temperature difference of 10 °C between the inside and outside to work.
  4. Table Look-up (Building Catalog)
    There are complex databases containing U-Values of generic building elements ordered by element material and year of construction. With these databases, the U-Value of a specific element is calculated by adding all materials contained within the specific element (e.g. specific wall = 20cm concrete + 20cm glass wool). While this method is very simple and quick, it does not produce an accurate U-Value, only an approximations.

How does a U-Value Measurement with the Heat Flux Method work?

The following simplified description illustrates how straightforward a U-Value Measurement can be performed by the U-Value Kit.

  1. Choose an optimal measurement spot on the building element of interest.
  2. On the inside of this spot, place the heat flux sensor and one temperature sensor.
  3. On the outside of this spot, place the second temperature sensor.
  4. Connect all three sensors to the data logging unit.
  5. Start the measurement process (via your PC).
  6. Evaluate the U-Value of the wall element in the PC software included in the U-Value Kit.

If you are interested in a more detailed description, please download the Application note (on the right hand side).

“The U-Value Kit has helped us to a great extent in our in-situ measurements of insulation materials. We used the sensor to determine the U-Values of various wall composites.”

– Prof. W. D. Constant, Louisiana State University

U-Value Kit

Free Download

Get the application note about U-Value Measurement for free. Provide your email address and get instant access (no activation required).

Easy to transport

The U-Value KIT easily fits into our solid transportation box.

Easy to mount

You can use normal adhesive tape to fix our sensors to any wall / window

Real-time review

You can review measurement protocols and graphs in real-time on your laptop.

Short measurement

If you do not need to follow ISO guidelines, you can measure U-Values also in less than an hour.

Buy the U-Value Kit online

Detailed information about the U-Value Kit is available in our online shop.

Take me to the online shop