Pulses per second ..........Question

[Lake Hunter]

When looking at PI units, what is the better pulse per second for deeper targets like gold ..... 600 PPS or 750 PPS ?

 

[Tony]

Lake Hunter,

Pulse delay and pulse widths are more important factors to consider if you are hunting the deeper gold.

Pulses per second (PPS) or the frequency of a PI has more to do with response speed and battery consumption.
I think interference reduction is also relevant to the frequency of a PI.

The frequency of PI's can vary hugely from a couple of hundred PPS to many thousands.

I hope this helps.

Tony.

 

[Lake Hunter]

n/t

 

[6666]

Its not the pps so much, its more the pulse width, and sample delay timing, however in THEORY maybe the 750 pps
could be slightly better but it depends on the circuit being used,
to quote reg

The pulse width is the time the pulse current is on. Increase the width and the coil current will increase on many if not most coils. This will or can result in some depth increase but does so at a price. More coil current takes longer to decay so the minimum delay that one might be able to use can increase. Thus, a longer pulse width can result in increasing the depth on large objects but make it more difficult to detect the smallest gold.

Pulse width is not generally something that is adjustable on many PI's. On the GS 5, at least on some versions, one could switch between 100usec and 200 usec pulse width. The longer width may have been 250 usec. I don't remember for sure. I never did see any improvement in depth with the longer pulse width but I was only testing some of the more common nuggets I have found in the past with none of them much over 1/2 oz.

Now, the 200usec width should do a little better on much larger gold and silver but would not usually will not allow the minimum delay to work on some coils that would work on the 100 usec setting.

So, part of the decision of what would be a single setting if there were no pulse width control was determined by what was to be the primary reason for the detector. For gold, generally, 100usec worked fine. Actually, 50 usec worked great for really small gold because it would allow for a little shorter delay to be used. However, one could see some depth loss on larger targets, so the 100 usec setting is a good compromise and is common on detectors such as the TDI.

 

[alexismex]

Hello Reg,
In field test where a 20 liter iron tank is buried at 1,80 meter with my pulse detector (fcy between 500 to 600 pps).... i can detect ( with coil 40cm) very little signal with 100usec pulse width.... but when i switches to 200 usec ...i can detect it easily ...but this is for iron ...don't know with gold....

 

[TheMarshall]

When looking at PI units, what is the better pulse per second for deeper targets like gold ..... 600 PPS or 750 PPS ?

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Regarding your query.

Generally, the more pulses per second (within limits), the greater the apparent sensitivity.

The number of Pulses Per Second...PPS.......or Pulse Repetition Frequency......PRF. does affect the sensitivity factor of a PI detector.

The environment ground factors, in which the detector is going to be employed, may impose limitation on this parameter.



This parameter ( PPS or PRF ), is only one of several other equally important factors...like pulse width and coil design, etc.