General Tools and Instruments HT20 - Manual (Page 17)

pressed within the past 60 seconds. That is the case even
when the unit is logging data. In other words, the LCD is
normally “asleep”.
To wake up the LCD, briefly press the MODE button. This
first press of the button will cause the LCD to resume
displaying the same indication that was on-screen when the
LCD was last put to sleep.
There are four possible display indications: (1) current
temperature in Celsius, (2) current temperature in Fahrenheit,
(3) current relative humidity (in %), and (4) current working
status. Each press of the MODE button changes the display
to the next indication in the sequence; pressing the MODE
button when the LCD is displaying the unit’s current working
status (4) resets the cycle to (1).
There are four possible working status indications:
• LOG: The unit is currently logging data
• - - -: The unit is in standby mode, ready to log data
• FUL: The unit’s internal memory is full and logging has been
stopped
• CON: The unit needs to be configured by software
When the LCD is displaying a temperature or humidity
reading, it also gives an indication if the reading is outside the
“acceptable” range of readings for that parameter—
assuming that high and/or low alarm setpoints were entered
during the Setup procedure. If an “up” arrow appears at the
left of the reading (see Fig. 1b on p. 7), the measured value of
that parameter is higher than its high alarm setpoint. If a
“down” arrow appears at the left of the reading, it is lower
than the low alarm setpoint for that parameter.
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HT20 - Manual–FINAL_REV_0316121_awb 3/16/12 4:02 PM Page 17