Finding pipes undeneath metal fence

[sako]

How do you guys do it? I have a Schonstedt GA-52CX Magnetic Locator, but when searching for pipes under cyclone or barbed wire fence, the nose is not much of help. Is there any other detector (like HoundDog) you are using which probably ignores the signal for the fence?

[hellsangle]

Read page nine of the manual:
https://www.schonstedt.com/wp-content/u ... l-2-17.pdf

Crazy Phil - Surveyor to Recorder

[Jim Frame]

I've been experimenting with a pinpointer:

https://www.amazon.com/Garrett-1140900- ... 00TADH9HA/

It doesn't replace a Shonestedt -- it has very limited range -- but it has some ability to tune out unwanted signals (like a chain link fence).

The attached photo is at a corner for which I had calculated a search location, which landed within a couple of feet of a braced steel pipe fence post. The Schonestedt wasn't useful, it was singing wildly no matter how I oriented it. I dug down about a foot at the search location, but didn't find anything except the concrete anchoring the steel pipe brace. I was about to call it lost when I decided to try out the pinpointer. It kept giving me a strong signal near the edge of the hole, very specific. I scraped the mud off the concrete and there was the rebar.

I now consider it a valuable adjunct to the Schonestedt, especially given the modest cost. It's small, light and comes with a belt holster, so it's very easy to bring along.

t1.jpg

[Peter Ehlert]

Dip Needle or Compass?
Works for me

[sako]

Dip Needle or Compass?
Works for me

How does it work, any pics?

[sako]

I've been experimenting with a pinpointer:

https://www.amazon.com/Garrett-1140900- ... 00TADH9HA/

It doesn't replace a Shonestedt -- it has very limited range -- but it has some ability to tune out unwanted signals (like a chain link fence).

The attached photo is at a corner for which I had calculated a search location, which landed within a couple of feet of a braced steel pipe fence post. The Schonestedt wasn't useful, it was singing wildly no matter how I oriented it. I dug down about a foot at the search location, but didn't find anything except the concrete anchoring the steel pipe brace. I was about to call it lost when I decided to try out the pinpointer. It kept giving me a strong signal near the edge of the hole, very specific. I scraped the mud off the concrete and there was the rebar.

I now consider it a valuable adjunct to the Schonestedt, especially given the modest cost. It's small, light and comes with a belt holster, so it's very easy to bring along.

t1.jpg

Jim, Can you explain how it operates? any settings?

[Jim Frame]

Jim, Can you explain how it operates? any settings?

I can't tell you anything about the technology employed, and I'm still a newbie as to use, but -- like a Schonestedt -- the closer you get to an iron object, the more audible signal you get. With a Schonestedt the frequency of the sound increases with proximity; with the pinpointer the frequency of the sound is constant, but the sound is intermittent (beep beep beep) and the closer you get the faster the beeps. It also vibrates in concert with the beeps, and you can turn the beeps off and rely solely on vibration if you prefer. And there's a small LED flashlight built in that's on all the time the unit is on, which can be helpful when working in holes.

As I mentioned earlier, the range is very limited -- maybe a foot or so -- so you need to have a pretty good idea of where you should be looking in order to make use of it.

There are 3 sensitivity levels, and a background cancelation feature. As I understand the latter (I haven't done any organized testing), if you turn the unit on while holding it near the object (e.g. chain link fence) you want to mask, it'll calibrate itself to that magnetic condition and only respond to objects that disrupt that background field.

The interface is the power button, with selections made via short or long presses and feedback via sound and vibration. Making selections takes some practice, as does remembering which press gets you which setting.

As I said, I'm still testing it out, but I've already made a practice of slipping it on my belt when hunting for monuments.

[Peter Ehlert]

Dip Needle or Compass?
Works for me

How does it work, any pics?

Magnetism, the needle points at ferrous metal. a Dip Needle is just a Compass in a fancy box, they work Great. Especially in tight spots where the electric gizmos are too big, and they just want to yell and can't point to what they see.

read this: https://www.pollardwater.com/product/aq ... /R-4927423
this is all we had 1970 to mid 1970's when the first Schonstedt came out.

When I was in Oregon in the late 1970's it was all low budget, I learned that a simple compass also works great, but it takes a little more finesse.

[sako]

Does anyone have experience with the "HoundDog"? or Schonstedt SPOT Magnetic Locator ?
https://youtu.be/b0Y18Gkl84o
https://youtu.be/qTKcbicQ3fo

[Lehmann]

I use the subsurface detectors with the digital meter that shows + or -. The bottom of the metal fence shows -, but as soon as you get over an iron pipe or rebar, it turns to *. Best tool when working along any type of metal fence.

[sako]

I use the subsurface detectors with the digital meter that shows + or -. The bottom of the metal fence shows -, but as soon as you get over an iron pipe or rebar, it turns to *. Best tool when working along any type of metal fence.

What's the brand and model you are using?

[Jim Frame]

the closer you get to an iron object, the more audible signal you get.

Replace "iron" with "metallic" in the above statement. I learned that the pinpointer picks up my gold wedding band just as well as it does a rebar.

I used it to good advantage again yesterday when looking for rebars that had been set in a lawn. They were close to the surface, so I didn't have to haul the Schonestedt with me -- I just staked out the expected locations, pulled the pinpointer out of its holster on my belt, turned it on and found the monuments. It's a one-handed operation, meaning I didn't have to set the prism pole down until it was time to dig.

[DWoolley]

Interesting tips on locator use.

We can all agree the monuments are, in most instances, the most important evidence of a boundary location. If monuments exist and the boundary is "resolved" without the monuments the boundary is incorrect in most every instance - it is only a question of the magnitude of the error.

There are few exceptions to missed existing monuments that are not clear cut negligence.

I have realized the locator is not completely reliable - regardless of the brand. I ask our crews to dig down a foot (in dirt) and sound again. We have found enough monuments doing this to make relying on the locator without digging unsettling and an unnecessary risk of negligence.

Last week, while on a monument preservation project, we could not hear anything in a street location. The crew dug down 0.25' and found a monument, the same for the next location, no sound and there was a record [cut] spike and a stamped [bronze/brass] washer. The balance of the monuments were set in an irregular shape and the crew didn't have calculations to search for the next 12-15 monuments. Unfortunately, the previous surveyor has said "searched, found nothing" and resolved the boundary. Ugh. I would take any bet most of those monuments will be found.

Lesson for me has been not to rely solely on a locator - under fences or in asphalt. Cut spikes and old PK nails do not have sound. The hint was an earlier record said "punched square head spike". Cut spikes accept a punch and are squared headed, start digging.

Was the last fella negligent for not chipping up a couple test holes before saying "searched, found nothing"? It doesn't take much effort to chip up 0.25' of asphalt or 12" dirt.

DWoolley

[PLS7393]

Was the last fella negligent for not chipping up a couple test holes before saying "searched, found nothing"? It doesn't take much effort to chip up 0.25' of asphalt or 12" dirt.

DWoolley

Everyone is so quick to call someone negligent. What type of monument are you searching for with a schonstedt? City of San Jose set 5/8" brass rod in concrete & punch at grade as their standard City Monument. Brass is non-ferrous so you need a cheap amateur grade metal detector to search after the city paves over and slurry seals. They will assist, but that means your client doesn't get his job done for another few weeks.

All cities/counties who pave over existing monuments which control a subdivision is, (in your terms) negligent. I personally have no problems pulling out my roto hammer to dig a hole in the street. I work well with those cities who have a staff surveyor, but the cities with a contract surveyor won't give you the time of day. I will no longer dig through AC that was not perpetuated and on a busy street. It makes me survey out further than planed, but my safety is more valuable than finding that monument. NOTE on map "GOOD SOUNDING UNDER AC, DID NOT RECOVER". if that makes me negligent, so be it, but I'll live another day.

[hellsangle]

What would the "expert measurers" do when all that you have is "occupational" evidence? Go three blocks away to a "monument"?!

Do the "expert measurers" confirm pedigree? Or treat the last Record of Survey or any monument as being paramount?

Without a Boundary Line Agreement or adjudicated boundary - they are all just "opinions", folks. (Remember: Mike's two tags 0.01 apart? Insane. Same with the same owner that had two surveys and now the wall is over 0.07'. Insane.)

That's the crazy-man's two cents

Have a nice weekend and looks like we're gonna get some measurable rain up her in the Northlands

[DWoolley]

...
Do the "expert measurers" confirm pedigree? Or treat the last Record of Survey or any monument as being paramount?
...
Without a Boundary Line Agreement or adjudicated boundary - they are all just "opinions", folks.
...

There are a handful of common themes in the litigation that I get involved with. A top five common theme in which the surveyor gets whacked professionally is by accepting the latest record or record monument. The surveyor accepts the job and clutches onto a couple of fresh monuments, death knell. Typical scenario is I follow up, having all the time in the world, and start to piece together original evidence of the boundaries. Practice tip, when a surface monument doesn't make sense, something is janky, pull it and look underneath it.

The idea it is "just opinions" greatly downplays the liability associated with being licensed and offering an opinion. It is not like politics or sports opinions offered over a beer with a neighbor. There is little latitude with professional opinions. When a surveyor offers the cavalier "opinion" defense those around the table smirk knowingly - sans the insurance counselor. I think my running tally on those opinions recently crested $5 million based on opinions that were in fact incorrect. That is the payouts, not the legal fees - which would include another several million in aggregate.

Keith Nofield, violating a statute is technically negligence per se - the burden shifts and a much lower burden of proof is required. Signed work product admitting a breach of duty makes everyone's life easier on the backend.

DWoolley

[mpallamary]

To me it is black and white.


https://archive.amerisurv.com/PDF/TheAm ... ol9No7.pdf

[Robert Martin]

How do you guys do it? I have a Schonstedt GA-52CX Magnetic Locator, but when searching for pipes under cyclone or barbed wire fence, the nose is not much of help. Is there any other detector (like HoundDog) you are using which probably ignores the signal for the fence?

Back the original post, I recently bought a new "Subsurface ML-3" from US Survey Supply in Bandon Oregon:

https://ussurveysupply.com/buy-surveyin ... r/locators

the display shows positive (+) or negative (-) polarity of the item it is piking up... I'm not a geek with this stuff, but I do know how to get results. Often I can run the locator along the bottom of a chain link and simply watch the polarity, typically the fence is negative (-), when the display switches to positive (+) I dig, this has been working very well, and I have quickly found several monuments right under the fences that would have taken quite a bit of searching to find otherwise. The change in the noise from the locator can be so subtle that you can't notice it, but it's funny, once you see the polarity on the display changing all of a sudden you notice the subtle change in noise.

[Lehmann]

I use subsurface, with the meter, I find it works great along metal fences.

[No_Target]

Does anyone have experience with the "HoundDog"? or Schonstedt SPOT Magnetic Locator ?
https://youtu.be/b0Y18Gkl84o
https://youtu.be/qTKcbicQ3fo

I also want to know if anyone has used the HoundDog? I've been looking at it for a while but never hear anyone talk about it.

[hellsangle]

For what its worth . . .

https://rpls.com/forums/topic/does-anyb ... hound-dog/

[RAM]

common sense, judgement and a good shovel.