baseline changes...
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Welcome, these forums are for professional and amateur scientists to discuss matters relating to radiation detection, and to facilitate friendly and honest collaboration. It is a requirement for all members to register using their real names and location. If your name has not already been used, feel free to use it as a login handle, otherwise add your name and location to the bottom of your posts as a default signature. Thanks for cooperating.
BUSINESS REGISTRATIONS
If you have a rad related business and want to post information about your products you may do so in the trading post, providing you first introduce your business formally in the introductions forum and add your business details in the signature sections so it is clear to everyone that your post has a commercial purpose.
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Karl D
- Posts: 3
- Joined: 03 Jan 2016, 06:49
baseline changes...
Hi..Karl D here from BC, Canada. I have been testing salmon and tuna with my gs setup for a couple years. I poured a 700lb lead base with an 80 lb counterbalanced lid, which gives 4" of lead around my Nal(Ti) probe. There is a 5/16 copper insert around the probe. My background has been flat since building it. When I ran tests on 2015 tuna in July everything was fine. When calibrating in Dec to test some roasred Korean seaweed I find a sharp spike of activity between 105kev to 140. I have dismantled and wiped everything but still have this spike. Is the probe wearing/worn out?
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Sesselmann
- Posts: 1388
- Joined: 27 Apr 2015, 11:40
Re: baseline changes...
Karl,
Hi and welcome to the forum..
If you suspect the problem is a technical fault I assume it appears regardless of weather the seaweed sample is in the container or not.
Some electronic noise on the baseline can produce a rapidly appearing peak at the low end of the spectrum, this is easily identified if you download a copy of Intune, and take a short recording. This will show you the sampled sound trace, and if the noise is electronic you will usually see very regular peaks, sometimes from 50 Hz ie they appear at 20 µs intervals, in which case it might be as simple as switching off a lamp or some other appliance.
Failing that, check your BNC cable, some cheap BNC cables are not rated for high voltage and eventually break down.
I look forward to hear how you go..
Steven
Hi and welcome to the forum..
If you suspect the problem is a technical fault I assume it appears regardless of weather the seaweed sample is in the container or not.
Some electronic noise on the baseline can produce a rapidly appearing peak at the low end of the spectrum, this is easily identified if you download a copy of Intune, and take a short recording. This will show you the sampled sound trace, and if the noise is electronic you will usually see very regular peaks, sometimes from 50 Hz ie they appear at 20 µs intervals, in which case it might be as simple as switching off a lamp or some other appliance.
Failing that, check your BNC cable, some cheap BNC cables are not rated for high voltage and eventually break down.
I look forward to hear how you go..
Steven
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Karl D
- Posts: 3
- Joined: 03 Jan 2016, 06:49
Re: baseline changes...
Thanx Steve...I suspect some kind of interference, and in looking at what has changed I just realised that I'm using a different inverter for my ac. Will keep looking...
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Karl D
- Posts: 3
- Joined: 03 Jan 2016, 06:49
Re: baseline changes...
Swapped inverters and the spike is gone. Guess that inverter puts out dirty ac...all's working normally...thanx again
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Sesselmann
- Posts: 1388
- Joined: 27 Apr 2015, 11:40
Re: baseline changes...
Glad to hear the problem is fixed. Noisy AC/DC inverters are a problem, so it's always good to avoid the cheaper ones, although I have seen expensive ones which are bad too.
