Description:
- Object ID: ALSA 2006.05.05
- Made by: Tellurometer (PTY) Limited
- Model: MRA 1 (Remote)
- Serial Number: 427
- Date Made: Introduced in 1957.
- Approximate size: Unknown
- Accessories: Comes with metal carrying case, eyehade, aluminium tube containing electronic parts, two plumb bobs, battery cable, bracket, cable extension cord. radio license.
- Condition: Good
Commentary:
The MRA1, introduced in 1957, was the first commercial tellurometer model to be marketed. Two slightly different instruments were used to obtain a measurement: one called the “Master” and the other the “Remote”. The Master is situated at one end of the line to be measured, the Remote at the other. Each unit has a phone enabling the operators to communicate with each other during the measurement process. The distance is achieved by measuring the phase of a frequency which has been modulated onto the carrier. The MRA1 was particularily suited for control and geodetic surveys due to its range of 30 to 50 kilometres.
Only the Remote is in the collection. The Society also has another MRA 1 in its collection but unfortunately, it as well only includes the Remote. However with it is a booklet “Simplified Instructions for the use of the Tellurometer “Micro-distancer.”
Source of Object: Donated by the Director of Surveys.
Notes: The other MRA 1 Remote unit in the Society’s collection ALSA 2016.01.02 was donated by the Surveyor General of Canada..
References: Visit article “The Skill of Chaining would be lost” – The Tellurometer and Sturman and Wright, The History of Tellurometer. for additional information.
Description by: Ed Titanich, October 25, 2024 and Gordon Olsson, November 30, 2025.