Fig. 1. The controls and physical structures
of the RH650
A. Humidity/temperature sensor
B. Removable hanger tab
C. LCD
D.
ON/OFF HOLD
button.
With meter off
, pressing
button powers it on.
With meter on
, briefly pressing
button freezes primary and secondary readouts;
pressing and holding button powers meter off.
E. M
AX/MIN
button. For all parameters except moisture
level,
pressing button once displays highest reading
since entering that measurement mode.
Pressing
button twice displays lowest reading
since entering
that measurement mode. Pressing button a third
time resumes measurement and display of same
parameter.
Also used to enter alarm set mode
.
F.
ZERO
button.
With meter off
, used to disable Auto
Power Off (APO) function. In measurement mode, used to reset baseline of pinless moisture
(
MOIST INT
) measurements.
In memory mode
, used to clear stored readings.
G.
UNIT
button.
In measurement mode, each press toggles between Imperial and metric
measurement units for the following parameters: Ambient Temperature & Dew Point (°F or
°C); Absolute Humidity (mg/L or g/m
3
); Mixing Ratio (GPP or g/kg); Barometric Pressure and
Vapor Pressure (mBAR or KPa).
In memory mode, used to clear
stored readings.
Also used
to enter alarm set mode
.
H.
<DN
button.
In measurement mode, each press shifts mode selector one position to the
left. In memory mode, each press decrements record counter
by one digit.
In alarm set
mode, each press decreases alarm setpoint
by 0.1%.
I.
UP>
button.
In measurement mode, each press shifts mode selector one position to the
right. In memory mode, each press increments record counter
by one digit.
In alarm set
mode, each press increases alarm setpoint
by 0.1%.
J.
STORE/ENTER
button.
In measurement mode, stores both displayed readings
in memory
when pressed and held for >2 seconds.
In alarm set mode, saves displayed Hi alarm
setpoint
and advances to Lo alarm setting, or saves displayed Lo alarm setpoint and
resumes measurement mode.
In memory mode, exits memory
mode and resumes
measurement and display of last selected parameter.
K. Jack for included pin-type moisture probe
L. Pinless moisture sensor (on back)
M. Battery compartment (on back)
5
A
B
C
D
F
G
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J
M
E
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