This comprehensive guide serves as a functional manual overview, operational reference, and historical guide for Hilger & Watts optical theodolites, focusing on popular models like the Microptic No. 1 and No. 2. 1. Introduction to Hilger & Watts Instruments Company Origins
If you possess a serial number, contacting the UK surveying historical society may yield a matching scanned document.
Employs a coincidence reading system that averages opposite sides of the glass circle to eliminate eccentricity errors.
If you rotate the instrument 360 degrees and the optical plummet moves off the ground mark, the plummet's internal reticle screws need adjusting.
The workhorse of civil engineering and land surveying, featuring direct reading or estimation down to single arc-seconds. hilger watts theodolite manual
The plate levels on a Hilger Watts theodolite are extraordinarily sensitive (commonly 20 seconds per 2mm division). The manual details the step-by-step "rotation and half-division" method for calibration—a process not intuitive to a modern user.
Rotate the instrument back to the original position to verify, and check all 360 degrees of rotation. If the bubble shifts out of the center lines at any point, the plate level requires calibration (see Section 5). 3. Reading the Optical Scales and Micrometer
Look through the small circle reading eyepiece located next to the telescope.
Depending on the model (No. 1 or No. 2), you will see illuminated glass scales. This comprehensive guide serves as a functional manual
Ensure the tripod head is visibly level by eye over the ground mark.
Depending on the model year, the instrument will feature either a optical plummet built into the alidade/tribrach or require a traditional mechanical plumb bob.
General engineering, construction, and lower-order land surveying.
to align the instrument directly over the ground marker by sliding it across the tripod head. Adjust the tripod legs to level the circular bubble for rough positioning. three footscrews on the base to precisely center the plate level bubble If you rotate the instrument 360 degrees and
Their theodolites (especially the TM series ) were considered the "Rolls Royce" of survey instruments, competing directly with Wild Heerbrugg and Kern. They feature read via an optical micrometer, rather than the older vernier scale.
In many models, you will see two sides of the circle (e.g., 0° and 180°). A micrometer knob is used to align (coincide) the markings [2].
Point the telescope toward a blank background (like the sky or a white wall).