The School of GeoSciences has four Lacoste and Romberg gravity meters. These instruments are one of the School’s “facilities”, meaning that they are a long-term equipment asset and that they can be made available on loan to users across the University, and from outside the University, who have a need to make some gravity measurements. Anyone wishing to use the instruments should contact Hugh.Pumphrey@ed.ac.uk in the first instance.
L and R gravity meters are usually referred to by their serial numbers. The original model G series have a calibrated range that covers the entire world. The model D series have a greater precision but are calibrated over a more limited range. The instruments we have are:
- G-275. This instrument was purchased in 1971 and is as it was when purchased, apart from routine servicing. It has a smaller case than usual and is very basic, with none of the optional extras.
- D-145. This instrument was purchased in 1989 and is as it was when purchased, apart from routine servicing. It has both a fine and a coarse dial, combining the merits of the original model G and model D instruments. It also has the optional beam galvanometer, analogue output and electronic levels.
- D-154. This instrument was purchased in 1989 and was at the time similar to D-145. It has since been upgraded by ZLS (https://zlscorp.com/) to add a high-precision electronic readout system.
- D-92 This is a single dial model D instrument. It has the optional beam galvanometer with analog output and the variable damping feature. I found it abandoned in the back of a cupboard and used it as a test case to ensure that a new power supply was not going to damage the working instruments. In the process I found that it does work, but not well. It is sometimes used to provide the live gravity tide plot when D-145 is not available. It is on my list to be serviced by ZLS.
![Gravity meters](https://blogs.ed.ac.uk/hughpumphrey/wp-content/uploads/sites/958/2022/07/D-154_G-275_tideswell.jpg)
There is further, more informal, information available about the instruments in Hugh Pumphrey’s blog, including the following posts:
- More information on the instruments
- Data from a recent field trip including a video demonstrating how the instruments are used.
- Detection of a nuclear test
- Baseplates
- An partly-solved mystery concerning the calibration tables for D-154