Wink of knowledge: Air & N2 – DGF-I1 density sensor for gases
Why this test?
Since air and nitrogen have a similar density range, the test results confirm our expectations for the DGF-I1 density sensor.
What is a wink of knowledge?
And the speed at which you get to the result counts more than the perfect (scientific) approach?
For this reason, we have introduced a wink of knowledge.
Science with a twinkle in its eye, so to speak.
We’re not looking to prove something scientifically, but rather to quickly demonstrate something pragmatically. If you’re interested, we would be happy to discuss these results in more detail with you and your project.
Which gases were used?
- Nitrogen 4.5
PanGas (material number 6430112)
- Dry air
For this purpose, the listed gases were passed through the sensor for a period of time at a constant flow rate.
A logging function was used to record a reading for the density, temperature, pressure and reference density once every second.
at 0 °C, 1.01325 bar abs
Dry air (Air)
at 0 °C, 1.01325 bar abs
The TrueDyne sensor
It is screwed directly into the gas pipe or gas tank with the integrated connection; a filter protects against contamination.
The readings are transmitted to the higher-level system via an RS485 interface.
The response time of 5 seconds makes a density measurement directly in the process possible – the measurement does not have to be interrupted.
Hydrogen (H2) • Helium (He) • Nitrogen (N2) • Oxygen (O2) • Carbon dioxide (CO2) • Argon (Ar)
Media which differ from the media listed above can be used after individual clarification, if necessary.
For example Neon (Ne) and Krypton (Kr).
Density: <0.1 kg/m³
Temperature: <0.8 °C
Pressure: <0.04 bar
With field adjustment density <0.05 kg/m³
Density: <0.015 kg/m³
Temperature: <0.06 °C
Pressure: <0.005 bar
Permissible density measuring range:
0.2 … 19 kg/m³
Permissible pressure range:
1…10 bar (absolute)
Gas mixtures with argon (Ar) only up to
max. 9 bar (abs) must be used.
Burst pressure 30 bar
Five thermal mass flow controllers (MFC) connected in parallel allowed the various pure gases to flow through the sensor in alternation.
The installation of the exhaust at the side opening of the sensor favours the gas exchange in the housing, which optimises the reaction time.
- Gas supply
- MFC: Vögtlin red-y GSC-B9SA-BB23
- Static mixer: Swagelok
- Density sensor: TrueDyne DGF-I1
For this purpose 100 measuring points per medium were used in the steady state.
- Reference density Air – dry air
- Reference density N2 – nitrogen
A. Data extract table A
B. Data extract Table B
The same readings were used as for the mean value calculations; the class width was defined as 0.001 kg/m³ for both media.