Remote control your miniRUEDI

Setting up a remote control for the miniRUEDI is easy with the right software. So far, we really like DWService! It’s open source, and you can use if for free. The DWService system works by installing an «agent» software on the miniRUEDI computer, which connects to an account on the DWService website. The website allows screen sharing, file uploads and downloads, shell access, a text editor, and other useful remote management tools for the miniRUEDI computer.

Connecting the agent to the DWService website requires a code, which is generated from the DWService account. To this end, you’ll either create your own account (it’s free!), or you can ask us to create a code for you from our DWService account.

Here’s how to install and configure the DWService agent software on the miniRUEDI computer:

  1. Connect the miniRUEDI computer to the internet.
  2. Download and and save the installer file (do not “open as text”).
  3. Install the DWService agent by using the installer (run the commands in a Terminal window):
    1. Change to the directory where you downloaded the installer file. For example:
      cd /home/ruedi/Downloads/
    2. Make sure the installer file is executable:
      chmod +x dwagent.sh
    3. Run the installer file with admin permissions (you may have to enter the admin password), using your DWService code. For example, if your code is 123-456-789:
      sudo ./dwagent.sh -silent key=123-456-789
  4. Once the installation of the DWService agent is completed, the miniRUEDI computer should be accessible via the internet using the DWService website.

New Software!

We spent some time to revamp the miniRUEDI software for instrument control and gas analysis!

The new software is not only prettier but is also easier to configure. You don’t need to write Python code anymore (but you still can!).

If you want to try the new software with your miniRUEDI, please get in touch with us.

Deconvolution and compensation of MS interferences

For many gas species (e.g., He, Ar, Kr, N2, O2, CO2) the partial pressures measured with the miniRUEDI can usually be calibrated by simple peak-height comparison relative to ambient air or gas standard with well known partial pressures. However, depending on the composition of the analysed gases, the ion currents measured at certain m/z ratios may result from overlapping ion currents of multiple species (for example CH4, O2 and N2 at m/z=15 and 16; or Ne, Ar and H2O at m/z=20).

We developed a method that extends the miniRUEDI peak-height comparison in order to resolve such overlap interferences. The method uses spectral deconvolution and was incorporated in the ruediPy software toolbox. The deconvolution method substantially improves the analytical accuracy in situations where mass-spectrometric interferences cannot be avoided.

Full details are availalble in the original publication: M.S. Brennwald, Y. Tomonaga, R. Kipfer: Deconvolution and compensation of mass spectrometric overlap interferences with the miniRUEDI portable mass spectrometer, MethodsX, 2020, doi: 10.1016/j.mex.2020.101038

Running on Batteries

We frequently get asked how to run the miniRUEDI on batteries for field work at remote locations with no mains power.

Here are the basics to run the miniRUEDI on batteries:

  • The miniRUEDI runs on a voltage of 24 V.
  • The miniRUEDI draws about 2 A current during normal operation, and up to about 5 A or slightly more during startup of the pumps.
  • You need a fuse. Batteries do not like short circuits or similar mishaps. A 10 A rating should be fine.
  • Unplug the 24 V connections of the main power supply unit in the miniRUEDI, and connect the batteries to the miniRUEDI instead.

There are many ways to set up a battery power supply, but here is a simple setup that uses two simple «12 V car batteries»:

The capacity of the batteries determines how long they will be able to supply power to the miniRUEDI. Two of the typical «12 V car batteries» with a capacity rating of 60 Ah may last up to a full day before they need to be recharged.