(math-standard-units): Give exact conversion for tsp.

2 files changed, 8 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index c9452fde9db..df38de29e08 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2007-08-17  Jay Belanger  <belanger@localhost.localdomain>
+
+        * calc/calc-units.el (math-standard-units): Give exact
+        conversion for tsp.
+
 2007-08-17  Bob Rogers  <rogers-emacs@rgrjr.dyndns.org>  (tiny change)
 
         * progmode/cperl-mode.el (cperl-look-at-leading-count)
diff --git a/lisp/calc/calc-units.el b/lisp/calc/calc-units.el
index ae94fc43ae1..3724490169a 100644
--- a/lisp/calc/calc-units.el
+++ b/lisp/calc/calc-units.el
@@ -89,7 +89,9 @@
     ( ozfl    "2 tbsp"               "Fluid Ounce" )
     ( floz    "2 tbsp"               "Fluid Ounce" )
     ( tbsp    "3 tsp"                "Tablespoon" )
-    ( tsp     "4.92892159373 ml"     "Teaspoon" ) ;; (approx) ESUWM
+    ;; ESUWM defines a US gallon as 231 in^3.
+    ;; That gives the following exact value for tsp.
+    ( tsp     "492892159375*10^(-11) ml" "Teaspoon" ) 
     ( vol     "tsp+tbsp+ozfl+cup+pt+qt+gal" "Gallons + ... + teaspoons" )
     ( galC    "galUK"                "Canadian Gallon" )
     ( galUK   "454609*10^(-5) L"     "UK Gallon" ) ;; NIST