Datasheet

Datasheet EK-H4
www.sensirion.com Version 4 – July 2015 5/8
Figure 8 EK-H4 software window before measurement starts.
Sensors are displayed in different colors.
4.5 Temperature and Humidity Measurement
Measurements are started and stopped by the Start/Stop
button. The measured data are displayed in the
Measurement Data table. The measurements which are
displayed in this table can be selected in the context menu
which appears when the right mouse button is clicked on
the table.
Two plots are available, which display the progress of a
measurement over time. The measurement can be
selected in the list below the plot. The scale of the axes
can be altered by pressing the left mouse button on the
axis and moving the mouse. The plot can be dragged
using the left mouse button. The right mouse button can
be used to display a context menu, which offers functions
to print or copy the plot, or to set auto-scale options for the
axes.
Figure 9 Software surface during measurement. Displayed
values may be selected via menus at the bottom of the window.
4.6 Calculated Values
Relative humidity and temperature data are measured by
the sensors. From this data dew point and absolute
humidity values are derived.
4.7 Settings
In the settings section the measurement interval can be
chosen. The default configuration is 1 second.
4.8 Data Logging and Data Export
The data displayed in the measurement plots is kept in
memory. The measured values can be exported to a CSV
file using the menu item File/Log to file. The measurement
data can be cleared under the menu item View/Clear
Graph.
4.9 Heater and Fast Conversion
Behind every sensor there are two tick boxes, one to
activate the in-built heater and one to activate a fast
conversion mode.
The heater can be used as a simple functional test. After
switching on the heater, the temperature of the sensor
should increase, while the humidity signal should drop.
Please note that the heater power is different for every
SHTxx sensor. Additionally, the temperature elevation that
can be achieved through the in-built heater depends on
the temperature itself (at higher ambient temperature a
smaller temperature increase is achieved), the operating
voltage (higher operating voltages lead to higher
temperature increases) and on the thermal coupling of the
sensor to the environment.
The fast conversion mode activates a different
measurement command which has a higher noise level.
For SHT1x, SHT7x and the SHT2x series a measurement
with a lower resolution is started. While for the SHT3x
series the repeatability is changed to the low repeatability
mode. The default command (tick box not active) issues a
measurement command with the smallest noise level (high
resolution or high repeatability mode), except for the
SHT1x/SHT7x series, where the low resolution mode is
active per default.
4.10 Firmware Update
Starting from firmware version 2.4 (see section 3.2 on how
to read out the firmware version) it is possible to update
the firmware through the Viewer Software. If you have a
EK-H4 box with version below 2.4 you can use the Viewer
software Version 2, which is available from our webpage.
It does support the functions (Heater, Fast Conversion and
Firmware Update Function).