Sensor or Measuring Instrument: What Does Dracal Offer?

Dracal PTH200 components highlighted: USB plug, sensor and wire

The official definition (1) of a sensor is: a device that responds to a physical stimulus and transmits a resulting impulse. It must always be used in conjunction with other electronic components in order for the signal to be interpretable.

However, Dracal measuring instruments are called “sensors” in the air pressure and temperature sensor markets. So are the instruments of our competitors. 

What is a USB sensor?

A USB sensor is a measuring instrument that communicates via USB. The USB sensors for temperature, relative humidity, atmospheric pressure, etc. available on the market are in fact complex instruments used, among other things, for data logging. These devices fall into two broad categories: data loggers and instruments of a data acquisition system. Within these categories, please note that data logging can also be performed using a medium other than USB communication.

When you purchase a Dracal Technologies measurement instrument, you want a USB sensor that is immediately functional with free software tools for viewing and logging your environmental data, as well as integrating it into your own systems and software. But did you know that with this single blue housing there is much more than a "sensor"?

Anatomy of a Dracal product

Dracal PTH200 with components numbered: USB plug, sensor and electronic housing

 

[1] External probe with PET wire and mesh end

[2] Temperature and relative humidity sensor protected by a PTFE membrane

[3] Wire connecting the sensor to the electronic housing, with resistance to disconnection

[4] Electronic housing with CPU and, in the case of the PTH family, a barometer

[5] USB A to mini USB cable

In the previous diagram, you may have noticed that the temperature and humidity sensor is only a small part of the instrument; and that the atmospheric pressure sensor is located in a different place. Thus, when we speak of a “USB sensor”, we are deliberately omitting the description of the whole wire structure and the electronic housing.

Dracal Technologies' complete offer

The measurement instruments offered by Dracal Technologies are USB sensors that are part of a complete data acquisition system, which includes a graphical user interface software and command line tools for direct access to the data measured by the sensors. In addition, the compact and convenient “USB stick” format can be converted into a Virtual COM Port for integration into existing measurement systems that communicate in this way. Even better, the Mix & Match system allows you to have as many different instruments connected, all of which will be processed simultaneously and in a harmonized manner.

What if I only want a sensor?

If you are looking for a sensor whose CPU does not already contain a complex program to interpret your environmental data, you should know that it is possible to find one. For example, Sensirion is a company that sells sensors. In fact, Dracal Technologies offers a USB adapter for the Sensirion SPS30 particulate matter sensor.

Also, to measure temperature, some probes are in fact sensors: the thermocouple and the RTD probe. The thermocouple has two junctions of two different metal wires that will generate a potential difference in response to a temperature change (2). The RTD probe, on the other hand, is made of a metal whose resistance changes with temperature. When the probe is placed inside a very low current electrical circuit, this resistance can be measured (3). Dracal Technologies also offers USB adapters for thermocouples and RTD probes

Dracal Technologies' adapters are designed to interpret the electrical signals from the sensors and direct them to a USB output. This is an efficient way to connect a measuring instrument to a computer, which will allow it to compile your data.

In short

By putting on one side the official definition of a sensor quoted at the beginning of this article and on the other the real use and market studies, the usual nomenclature is slightly confusing, since our devices include other elements than a sensor.

We therefore choose to use the usual nomenclature for our products, but be aware that a Dracal measuring instrument is a precision tool consisting of a sensor, but also other components to allow you to make your measurements a simple step in your projects.

For questions or comments, contact us!

 

References

  1. Merriam-webster.com. “Sensor,” 2022. https://www.merriam-webster.com/dictionary/sensor.
  2. Sterling Sensors UK. “Thermocouple Technical Reference Information,” 2019. https://www.sterlingsensors.co.uk/thermocouples#What%20is%20a%20thermocouple.
  3. TE Connectivity. “Understanding RTDs,” June 24, 2022. https://www.te.com/usa-en/industries/sensor-solutions/insights/understanding-rtds.html.