Description:
- Object ID: ALSA 2015.04.03
- Made by: Tellurometer (PTY) Limited – Plessy Group
- Model: MRA 3
- Serial Number: 1636
- Date Made: introduced 1963.
- Approximate size: 0.1 cm (l) [including dome] X 30.1 cm (w) X 30.5 (h) [including leather handle]
- Accessories: A headset that has a microphone and speaker attached; a cable for hooking an external battery to the instrument and a small box of fuses. A small black plastic psychrometer 20 cm (L) [when folded inside] X 3 cm (diameter). The psychrometer consists of two mercury thermometers and one cotton wick (for wetting) one of them. There are many graduations for determining meteorological readings. There is a green binder that includes instructions for various types of instruments and operating instructions for each of them..
- Condition: good
Commentary:
Unit No 2 (as indicated by a plastic label within the control panel), this is one of two similar units that work together to measure distances electronically. Manufactured by the Plessy Group. The label on the top of the instrument is marked “MODEL MRA 3 SER. No 1636” and a metal tag indicates “MICRO-DISTANCER TELLUROMETER MADE IN SOUTH AFRICA BY TELLUROMETER (PTY.) LTD.CAPE TOWN”.
Behind the cover of the operating panel (when it is removed) one will find various dials, knobs and switches for operating the instrument for determining a distance. Also behind this panel is a large removable battery storage compartment and various female plugins for hooking up the external battery and microphone. The bottom of the instrument has a square base with a female thread for attaching the instrument to a tripod.
The instrument is carried in a large canvass bag that is supported by a metal back packing frame. The bag has two additional carrying pouches. There are various flaps for covering the top of the instrument and the pouches. There are many woven straps for holding down the covers and for securing the back pack to the person carrying the equipment..
Source of Object: Donated by Hamilton & Olsen Surveys Ltd.
Notes: Unit No. 1 ALSA 2015.04.04 is also part of the collection.
References: Visit article “The Skill of Chaining would be lost” – The Tellurometer for additional information.
Description by: Entered by Ed Titanich, October 29, 2024.