Manual

IN-E-HL-NT-V2_12
Rotronic AG
Bassersdorf, Switzerland
Document code
Unit
HygroLog HL-NT data logger:
instruction manual
Instruction Manual
Document Type
Page
13 of 48
Document title
© 2009-2012; Rotronic AG IN-E-HL-NT-V2_12
The HygroLog HL-NT has a red LED which can be set with HW4 to flash whenever the value of
any parameter corresponds to an alarm condition. The LED can be set to flash only as long as
the alarm condition exits or it can be set to provide a durable alarm and, in this case, it will to
keep flashing until the alarm is reset.
The HygroLog HL-NT can also be set with HW4 to beep for 5 seconds when there is an alarm
condition. The HygroLog HL-NT will beep only once, when the condition occurs.
Log files do not record the existence of an alarm condition. However, when the contents of a log
file are viewed as a data table with the HW4 software, values that correspond to an alarm
condition are printed over a red background, based on the alarm settings that HW4 downloaded
from the logger.
2.8.5 Display-Sleep function
This function can be enabled and configured only with the HW4 software.
Using the Display Sleep function can substantially extend the lifetime of the battery. When the
Display Sleep function is active, the LC display of the HygroLog HL-NT stays blank. The Display
Sleep function is effective both in the measure and in the record mode.
The display of the HygroLog HL-NT can be set to be always on. It can also be set to automatically
go blank after 30 seconds, 1, 5, 10 or 20 minutes when no key is being pressed or when there is
no communication with a PC. If the HygroClip NT was in the function menu at the time the display
goes blank, it automatically exits the menu.
The HygroLog suspends the Display Sleep function whenever a key is pressed. The function is
also suspended when external power is available or when the logger receives a communication
request (for example from a PC
1
). When the display comes up again, it shows by default the
measurements from the probe that was selected last.
1
When the HygroLog HL-NT is connected by means of a docking station to a PC and HW4
is running, you should use an external AC adapter to power both the HygroLog HL-NT and
docking station. HW4 can be set to use a polling interval as short as 5 seconds to interrogate all
instruments connected to the PC and this could cause the battery life time to be sharply reduced.
2.9 HygroClip 2 probe functions
2.9.1 Simulator function (validation of the signal transmission):
If so desired, transmission of the HC2 probe output signals can be validated by using the probe
simulator function. The HW4 software is required to enable and configure this function. When the
function is enabled the probe generates digital and analog signals corresponding to values
specified by the user.
2.9.2 Sensor failure detection and fail safe mode:
The HygroClip 2 probe automatically detects a sensor failure such as a shorted or open sensor.
This information is passed to both the HygroLog HL-NT and HW4 software. The optional display
of the HygroLog HL-NT will show an alarm message. The HygroClip 2 probe can also be
configured with the HW4 software to generate a "safe or readily identifiable" fixed value for
humidity and temperature in the event of a shorted or open sensor.