999
ABUS34 KPWM 172108
PNSPWM
   MEZ001>030-NHZ001>010-013-014-180000-
   PUBLIC INFORMATION STATEMENT
   NATIONAL WEATHER SERVICE GRAY ME
   4 PM EST WED FEB 17 1998

   ...ALLAGASH TEMPERATURE SENSOR FOUND TO BE IN ERROR...
   ...VAN BUREN RETAINS MAINE STATE MINIMUM TEMPERATURE RECORD...

   THE RECORD FOR THE COLDEST TEMPERATURE EVER RECORDED IN THE STATE OF
   MAINE CONTINUES TO BE 48 DEGREES BELOW ZERO...SET AT VAN BUREN ON
   JANUARY 19 1925.  THE NATIONAL WEATHER SERVICE HAS DETERMINED THAT
   THE -55 DEGREE TEMPERATURE RECORDED BY A NATIONAL WEATHER SERVICE
   TEMPERATURE SENSOR AT ALLAGASH DURING THE MORNING OF JANUARY 14 WAS
   IN ERROR.  TESTS SHOWED THAT THE EQUIPMENT REGISTERED A TEMPERATURE
   OF -55 WHEN THE ACTUAL TEMPERATURE WAS ONLY -38.


   THE INSTRUMENT WAS FIELD TESTED IN ALLAGASH ON JANUARY 25 AND THEN
   SENT THE NATIONAL WEATHER SERVICE'S TEST FACILITY IN STERLING
   VIRGINIA WHERE THE INSTRUMENT WAS TESTED IN A CONTROLLED
   ENVIRONMENT.  IN BOTH CASES...THE INSTRUMENT WAS FOUND TO BE IN
   ERROR.

   IN THE LABORATORY...THE TEMPERATURE SENSOR WAS EMERSED IN A SPECIAL
   FLUID THAT REMAINS A LIQUID TO -90 DEGREES.  TESTS WERE CONDUCTED AT
   10 DEGREE INCREMENTS FOR TEMPERATURES BETWEEN 100 DEGREES ABOVE ZERO
   TO 40 DEGREES BELOW ZERO.  THE READINGS FROM THE ALLAGASH INSTRUMENT
   WERE COMPARED TO THOSE FROM SEVERAL STANDARD PLATINUM RESISTANCE
   THERMOMETERS WHICH EACH HAVE AN ACCURACY OF 1/1000 OF A DEGREE.
   LIKE MANY OF US...THE ALLAGASH SENSOR PERFORMED BETTER AT MODERATE
   TEMPERATURES THAN AT EXTREMELY COLD TEMPERATURES.  BETWEEN 50 AND
   100 DEGREES ABOVE ZERO THE INSTRUMENT HAD A 1 TO 2 DEGREE ERROR.  AT
   AN ACTUAL TEMPERATURE OF ZERO DEGREES THE INSTRUMENT RECORDED -5.
   AT AN ACTUAL TEMPERATURE OF 20 DEGREES BELOW ZERO THE INSTRUMENT
   REPORTED A TEMPERATURE OF -29.  AND AT AN ACTUAL TEMPERATURE OF 38
   DEGREES BELOW ZERO THE INSTRUMENT REPORTED A TEMPERATURE OF -55.
   THE INSTRUMENT IS EXPECTED TO BE ACCURATE TO WITHIN 4/10 (0.4) OF A
   DEGREE.

   BASED ON THESE FINDINGS...THE TEMPERATURE IN ALLAGASH ON THE MORNING
   OF JANUARY 14 WAS -38 WHICH IS NOT A NEW STATE RECORD.

   HAWLEY/JENSENIUS
   NWS GRAY ME