The tripod is much sturdier than the puny one shown in the background of the picture above and which I initially bought for the range finder. The EQ1 telescope mount has proper slow motion drives with hand knobs and is far better than the adjustments on any cheap alt-azimuth mount with friction bearings and a tilt/pan handle to adjust. One adjusts the EQ1 mount for the equator so that the right ascension axis points horizontally in the following configuration:
The right ascension drive is extremely precise. The declination drive does slightly perturb the RA drive setting due to a tiny amount of slop in a bearing, but this does not prevent one doing hand adjustments using the slow motion knobs at the minute of arc level.
The laser beam diverges with an angle of 2 minutes of arc, and alignment with a small reflector target is easy with this mounting arrangement.
My first trial was with a target consisting of a pair of vehicle retro reflectors taped to a post 248 metres away over rough ground. The retro-reflecting surface measured 10 cm by 8cm which was smaller than the laser spot size at this distance - about 15 cm diameter. Alignment is done using a small sighting viewer on the rangefinder, and when the laser spot hits the retro-reflector a bright red spot is visible in the viewer and also with the unaided eye.
The readings I got in this initial trial fluctuated by about 1 or 2 cm - completely adequate reading precision for laying out a calibration course. Not that anyone would have ever laid out a 248 m calibration course with a steel tape over this rough, bumpy ground.
When I tried increasing the range to about 300m, I was not able to get a reading, so maybe the instrument is programmed to reject readings above 250m which is the stated maximum range, or maybe I had alignment problems since I could not see the reflected laser light at the increased range. More tests at ranges greater than 250 m are needed. However, even if range is limited to 250m it will still be very suitable for measuring short calibration courses in a single hop, or longer ones with two measurements.
I have started to evaluate the reproducibility using an 83m distance between a nail, and a small retorreflector of 4 sqcm area on a fence. I can position the laser ranger exactly, within 1 mm over the nail using a plumb bob:
Here is an magnified photo of the laser spot on the retroreflector. I think it appears white rather than red due saturation of the digital camera CCD. The scale is such that the small white patch is 5 cm above the edge of the retroreflector:
At 18 C today the reading came out consistently within 1 mm of 83.259 metres. I shall repeat this set up at other temperatures during the next few days. If reproducibility is confirmed, I will then steel tape a 249m cal course and then measure it with the laser.