Kestrel 4000 Instruction Manual page 3

IMPELLER Sapphire jewel
bearings on a user-
replaceable impeller.
IMPELLER COVER Swivel
cover protects impeller
when not in use.
DATA UPLOAD OPTICAL
COUPLER Software and
serial port interface
sold separately.
BATTERY DOOR
Sealed with o-ring to
keep product watertight.
BACK
TEMPERATURE SENSOR
Hermetically sealed precision
thermistor coiled to isolate from
case temperature.
HUMIDITY SENSOR Capacitive
sensor with secondary
thermistor to improve
accuracy and response.
SERIAL NUMBER
PRESSURE SENSOR Monolithic
silicon piezoresistive sensor.
Do NOT insert any objects
into this hole.
AAA BATTERIES
3