### Re: My Rangefinders TruPulse200X, Leica and Nikon

Posted:

**Mon Dec 09, 2013 9:27 am**Karl, Doug, Don, et. al.,

The TruPulse 200 and 360 both suffer when there is foreground clutter. It doesn't matter if you have either instrument set to closest or farthest mode. Obviously, you want the farthest, but it does little good. Yesterday, I was rechecking the height of the Arvol Looking Horse tree in MTSF. I had gotten 159.1 feet previously. I had hoped to use only the TruPulse 360 this time, but couldn't successfully shoot through the clutter. I had to resort to the Nikon Prostaff 440 to get crown distances. I reduce the longest distance I record by a foot when using the 440 and that puts my in close agreement with the TruPulse. Well, I got exactly 159.0 this time. I'm content.

With respect to the TruPulses, the inclusion of the gate on the 200X is sorely needed. Thank goodness it is working. BTW, I think LTI used some of our input in designing the 200X. I can't say that for sure, but they put a lot of stock in our testing and development of solutions to tree-measuring problems. I hope they hear us about the reticle.

In checking the accuracy of a tilt sensor, I set up an indoor exercise. I have a leveling laser that I use to establish the point on the wall that is level with the instrument's centroid when on a tripod. I then measure vertical distances up and down the wall and mark them. I use a tape for this. I establish the slope distances from instrument's centroid to the wall when aimed at each target. I use my Bosch GM80 and verify with the Bosch GLR825, or vice versa. When I'm confident that the distances are correct from centroid to each mark on the wall, I then record the angle using the TruPulse to each mark on the wall. To be precise, I have to adjust baseline and vertical distances from the centroid due to head swivel of the tripod. I have formulas for that, but once I know the distances, I can solve for the vertical angle associated with those distances and compare to what the TruPulse shows. In doing these kinds of experiments, having an instrument like the Leica or Bosch to get accurate distances is essential. Oh yes, I check on the angle by doing two sets of measurements, one using arctan and the other arccosine. I do this because the vertical distances on the wall are obtained via a tape. This gives me an independent measure of vertical distance that I can use to check the corresponding one computed by the Pathagorean Theorem using the level distance to the wall and the slope distance to a mark on the wall as obtained using the Bosch. It is all a little convoluted, but gives me a pretty good feel for what I can expect from the TruPulse tilt sensor.

Bob

The TruPulse 200 and 360 both suffer when there is foreground clutter. It doesn't matter if you have either instrument set to closest or farthest mode. Obviously, you want the farthest, but it does little good. Yesterday, I was rechecking the height of the Arvol Looking Horse tree in MTSF. I had gotten 159.1 feet previously. I had hoped to use only the TruPulse 360 this time, but couldn't successfully shoot through the clutter. I had to resort to the Nikon Prostaff 440 to get crown distances. I reduce the longest distance I record by a foot when using the 440 and that puts my in close agreement with the TruPulse. Well, I got exactly 159.0 this time. I'm content.

With respect to the TruPulses, the inclusion of the gate on the 200X is sorely needed. Thank goodness it is working. BTW, I think LTI used some of our input in designing the 200X. I can't say that for sure, but they put a lot of stock in our testing and development of solutions to tree-measuring problems. I hope they hear us about the reticle.

In checking the accuracy of a tilt sensor, I set up an indoor exercise. I have a leveling laser that I use to establish the point on the wall that is level with the instrument's centroid when on a tripod. I then measure vertical distances up and down the wall and mark them. I use a tape for this. I establish the slope distances from instrument's centroid to the wall when aimed at each target. I use my Bosch GM80 and verify with the Bosch GLR825, or vice versa. When I'm confident that the distances are correct from centroid to each mark on the wall, I then record the angle using the TruPulse to each mark on the wall. To be precise, I have to adjust baseline and vertical distances from the centroid due to head swivel of the tripod. I have formulas for that, but once I know the distances, I can solve for the vertical angle associated with those distances and compare to what the TruPulse shows. In doing these kinds of experiments, having an instrument like the Leica or Bosch to get accurate distances is essential. Oh yes, I check on the angle by doing two sets of measurements, one using arctan and the other arccosine. I do this because the vertical distances on the wall are obtained via a tape. This gives me an independent measure of vertical distance that I can use to check the corresponding one computed by the Pathagorean Theorem using the level distance to the wall and the slope distance to a mark on the wall as obtained using the Bosch. It is all a little convoluted, but gives me a pretty good feel for what I can expect from the TruPulse tilt sensor.

Bob