Double Probe Nuke

[BigH]

- I've run across a spec today that mandates the use of a double probe nuclear density gauge. What is meant by double probe? I've always just said to use a nuke.

 

[GeoPaveTraffic]

Could they mean a nuke with two radiaion sources? Of course every nuke I've ever seen has two sources, one for density and one for moisture.

Otherwise, I have no idea.

 

[jdonville]

BigH,

See the following:

http://www.eng-tips.com/viewthread.cfm?qid=127494

http://www.eng-tips.com/viewthread.cfm?qid=127670

Jeff


Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com

 

[BigH]

Damn-it, wished that damit had given the url of the gauge he found.

 

[BigH]

Check:

http://www.cpn-intl.com

leads to a brochure on their Dual Probe Gauge : MC-S-24

In doing a search on MC-S-24, I ran across a few articles on agriculture. There was one article on wheeled and tracked liquid manure spreaders travelling over soft ag land. Maybe we should learn a bit more of the mechanics of soils in Aggie-land.

Anyway - off the point, it reminded me of a story that my mentor told. Seems he "missed" the korean war (from Kiwi-land) but in University he carried out a study of how to determine if a tank could safely cross a paddy field. Ended up that they shot 45's into the ground and measured the depth of penetration and from correlations could tell if it was okay or not. Of course, this wouldn't likely work on hypersensitive Norweigan clays that stopped many a German Tiger tank - not the first one but either the second or the third! Remoulding effect.

 

[eric1037]

It seems kinda sleazy to specify a piece of equipment that is only produced by one company.

 

[jdonville]

eric1037,

When you get right down to it, *every* piece of equipment was produced by only one company at sometime or another. It's called "building the better mousetrap".

The real questions are, how well does it work? and, is it so much better than the single-probe gauges normally used?

Jeff


Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com

 

[eric1037]

I would think that the advantage of the dual probe machine would be that it would only test soil at the particular depth that you want.

The single-probe machine relies on the body of the machine and actually partially tests the soil between the tip of the rod and the body.

 

[BigH]

That is true - in RCC work, the depths of a layer are larger than normal and this permits a 60cm check on density - sort of like cross hole seismic I think. Maybe there are other sources now, but none came up on my search.