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
11 of 48
Document title
© 2009-2012; Rotronic AG IN-E-HL-NT-V2_12
Each individual probe input can be associated with a different parameter.
Note: depending on whether dew point or frost point was selected, both the HygroLog HL-NT and
HW4 will display either the symbol Dp or the symbol Fp for values below freezing. The symbol Fp
indicates that the value is a frost point as opposed to being a dew point. Regardless of the dew
point / frost point selection, the symbol Dp is always displayed for values above freezing.
Some of the above parameters require barometric pressure as an input. When an analog
pressure probe is connected to one of the HygroLog HL-NT inputs, the logger can be set to use
the measurement from this probe. When no pressure probe is being used, a fixed pressure value
can be used. This value can be specified as part of the HygroLog HL-NT settings.
2.8.2 Data logging
Data logging requires that a flash memory card be inserted inside the logger. Using the HW4
software, log files can be set to one of the following formats:
● HW4 binary format [LOG]: files in this format are encoded and can be opened only with the
ROTRONIC HW4 software. HW4 does not allow any manipulation / alteration of the data and
requires a password to log in. Should the file be somehow modified, HW4 will give a warning
that the file is not an original.
● Text file format [XLS]: in principle, files in this format can be opened with any text editor and / or
imported into Microsoft Excel.
The log file format is a global setting of the flash memory card (changing this setting requires the
HW4 software). At any given time, the card records data from all inputs in either one format or the
other. Files of different formats can co-exist in the flash memory card. Binary files (protected) use
substantially less memory space than text files (unprotected).
The logging function is independently activated for each individual input. The HygroLog HL-NT
creates a separate file for each input that is to be recorded. Multiple inputs cannot be recorded to
the same file. The HygroLog HL-NT automatically generates each file name. A file name consists
of 8 digits followed by the extension LOG or XLS. The first 4 digits are the same as the last 4
digits of the logger serial number, the 5
th
digit is the same as the input number and the last 3
digits are a number between 000 and 999 used to differentiate log files created for the same
input. The last number that was created is retained in the non-volatile EEPROM and is updated
whenever a new file is created for the input. When the number reaches 999, the next update will
reset it to 000.
All files are located in the root directory of the flash memory card, including the logger event file
and the logger configuration file. Regardless of the memory card capacity, the root directory is
limited to a maximum of 250 files. This means that the memory card can hold a maximum of 248
log files, and that a card with this amount of files is considered to be full, even if all the memory
has not been used.
Using HW4, the following log settings can be defined individually for each input:
● Start date and time
● Stop date and time
● Log interval (minimum 5 seconds)