icon Kapiti gaigakaunta

stairway to heaven

icon the third day

21 March 2011
Now that's interesting. For a long time this detector has been sitting on the bench ticking away. The ticking was facilited by connecting a piezo-electric sounder to the output, and so it is now. The oscilloscope shows a slowly decaying pulse with steps which are probably related to the physical movement of the piezeelectric sounder. 5V per division vertical; 20µs per division horizontal. bloody quick Here it is with the sounder disconnected, a much shorter and taller pulse. Sadly the electronics stops working without the sounder so it will remain while I refactor things.

You may see that there are various different traces at different levels. There is a relationship between the size of the pulse and the energy level of the particle (cf. frequency and wavelength). This is the property used to do spectragraphic analysis with this sensor so I'm working towards capturing more properties of the pulse. 50V per division vertical; 0.5µs per division horizontal.

The sounder measured as 30nF so I replaced it with a 10nF capacitor.

The increases in counts per minute seem to be due to my influence rather than anything environmental.

icon index

icontwin peaks - highest levels yet
2 Dec 2012
iconlatest - most recent data here
21Oct2019 11:14
iconreview - up to date
26 May 2012
iconAm241 v2.0 - smoke alarm redux: hot
28 April 2011
iconAm241 - smoke alarm false start
22 April 2011
iconbias - increased voltage from 478 to 725V
21 April 2011
iconprejudice - snapshot of record before voltage increase
21 April 2011
iconperspective - tritium in local waterways
21 April 2011
iconspectra - gallery of spectra 30Mar-17Apr
17 April 2011
iconfall - southerlies eat radiation
5 April 2011
icontop model - Norwegian atmospheric projector
5 April 2011
iconrain - it's hot up north
27 March 2011
iconbulk bins - fiddling with PRA
25 March 2011
24 March 2011
iconproduction - just another plot of background
24 March 2011
icondimension++ - first 10½ hour run
23 March 2011
iconforth - a better regulator, discovering PRA
22 March 2011
iconthe third day - looking at pulses
21 March 2011
icontutu - rock is cold
20 March 2011
iconguff - te ahi kaa
19 March 2011