From 147d1306d9ccd53e763ac2497f01114c9bccf293 Mon Sep 17 00:00:00 2001 From: sevlat Date: Thu, 20 Oct 2022 19:21:35 +0300 Subject: [PATCH] Update gravity_data.rst Precision required for gravity measurements supposed to be 1:1000000000 (10 to the power -9) rather than 1:109. --- content/gravity/gravity_data.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/content/gravity/gravity_data.rst b/content/gravity/gravity_data.rst index c3ce8800..c475e963 100644 --- a/content/gravity/gravity_data.rst +++ b/content/gravity/gravity_data.rst @@ -13,8 +13,8 @@ Modern portable land-based instruments include automated leveling, data recording, and logging, but essentially their sensors are based upon variations of a mass on a spring. If the force on a spring is to be measured accurately to tell us geologically useful information about gravity, then -changes in spring length, :math:`ds`, must be measured with a precision of -1:109. Therefore, some form of "amplification" is required. A complete +changes in spring length, :math:`ds`, must be measured with a precision of :math:`10^-9`. +Therefore, some form of "amplification" is required. A complete discussion of instruments is beyond the scope of these notes, but some of the characteristics of the most common instruments are listed here.