
Section 11. Glossary
473
watchdogtimer
Anerror‐checkingsystemthatexaminestheprocessorstate,software
timers,andprogram‐relatedcounterswhenthedataloggerisrunningits
program.Iftheprocessorhasbombedorisneglectingstandardsystem
updatesorifthecountersareoutsidethelimits,thewatchdogtimer
resetstheprocessorandprogramexecutio
n.Voltagesurgesand
transientscancausethewatchdogtimertoresettheprocessorand
programexecution.Whenthewatchdogtimerresetstheprocessorand
programexecution,anerrorcountisincrementedinthe
WatchdogTimerentryoftheStatustable
(p.530).Alownumber(1to10)
ofwatchdogtimerresetsisofconcern,butnormallyindicatestheuser
shouldjustmonitorthesituation.Alargenumber(>10)oferrors
accumulatingoverashortperiodoftimeshouldcauseincreasingalarm
sinceitindicatesahardwareorsoftwareproblemmayexist.Whenlar
ge
numbersofwatchdog‐timerresetsoccur,consultwithaCampbell
Scientificapplicationsengineer.
weathertight
Describesaninstrumentationenclosureimpenetrablebycommon
environmentalconditions.Duringextraordinaryweatherevents,
however,sealsontheenclosuremaybebreached.
WebAPI
ApplicationProgrammingInterface(seesectionWebAPI
,formore
information).
Glossary.WildCard
acharacterorexpressionthatsubstitutesforanyothercharacteror
expression.
XML
Extensiblemarkuplanguage.
UserProgram
TheCRBasicprogramwrittenbytheCR3000userinCRBasicEditoror
ShortCut.
11.2 Concepts
11.2.1 Accuracy, Precision, and Resolution
Three terms often confused are accuracy, precision, and resolution. Accuracy is a
measure of the correctness of a single measurement, or the group of
measurements in the aggregate. Precision is a measure of the repeatability of a
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