1. Izon Science Support Centre
  2. qNano
  3. Troubleshooting: Pressure Module

Is my Pressure Reading Module (PM2) working?

When a Pressure Reading Module is attached to a qNano instrument, the software will recognise this and display the pressure/vacuum that has been applied from the VPM to the system.  

Pressure Leak test

  1. Start the Izon Control Suite Software and click on the Classic Capture mode.  
  2. Set the voltage slider to 0.1 V and turn on the voltage. 
  3. A pressure readout box will be displayed in the status line under the Signal Trace plot.  
  4. Prepare the VPM to apply pressure/vacuum i.e. set the plunger to it's "0" position and vent valve open (vent hole is seen). 
  5. Hold a finger over the hole of the VPM nozzle, close the vent valve and apply pressure/vacuum of 5 units. The software should correspond to the applied pressure/vacuum and show a stable positive or negative pressure reading, depending on the seal of your finger!  Failing this, repeat Steps 1 - 5 with a nanopore set up (baseline current visible). 
  • Make sure the tubes are completely connected over the barbs and the knurled nuts tightened.
  • Check that the fluid cell is not causing the leak i.e. repeat above steps. 
  • Check the O-rings on the vent valve and the nozzle are in good order. 

Things to be aware of

  • When the VPM is set to the low pressure range, the reading displayed on the software is likely to differ from the plunger setting. This is due to the small pressures it generates and other effects which cause it to vary. These effects include closing the vent valve quickly or abrupt movements of the plunger.
  • Avoid getting fluid in the nozzle as this may cause incorrect pressure application as well as introducing contamination. Should there be fluid in the nozzle, wash with deionised water and dry with compressed gas. To prevent fluid from touching the nozzle, never load more than 35 µL of fluid into the top fluid cell. 
  • Sometimes the automatic detection misses the presence of the pressure module (no pressure readings displayed).  If this happens, cycle the power to the instrument by turning it off, wait 10 seconds, then turn it back on.

    Contact Izon Support for assistance if unable to find the cause of a leak.