4
SDL550-EU-EN-V1.2-10/11
Selecting Meter Functions
The SDL550 can measure Moisture Content (%RH), Dew Point Temperature (
°
C/
°
F), Wet Bulb
Temperature (
°
C/
°
F), and Thermocouple Temperature (
°
C/
°
F). Press and hold the FUNCTION button
for 1.5 seconds to begin scrolling through the functions. Release the FUNCTION button when the
desired function is displayed. Refer to the table below.
Functions
Primary display
Secondary display
Unit of measure
Moisture Content
Relative Humidity
rh briefly displayed then the
Moisture Probe Temperature
RH% and
o
C or
o
F
Dew Point
Temperature*
dp display icon
°
C or
°
F
Wet Bulb
Temperature*
_et display icon
°
C or
°
F
Air Temperature
Thermocouple Temperature
tp briefly displayed
°
C or
°
F
Measurements
Moisture Content Measurements
1. Connect the Moisture probe to the jack at the top of the meter on the right
2. Switch the meter ON by pressing and holding the power button for 1.5 seconds
3. Press and hold the FUNCTION button to select the Moisture Content mode. When the Moisture
Content mode is selected, the display icon rh is briefly shown
4. Carefully remove the protective cap from the moisture probe. The probe tip is extremely sharp,
use caution
5. Insert the probe tip into the material under test far enough to cover the sensor’s openings
6. The meter will now display moisture content in %RH on the primary (upper) LCD digits
7. The secondary (lower) LCD digits will show the temperature measured by the moisture probe’s
built-in temperature sensor. Use the Setup mode to change the temperature units of measure
8. Note that the probe uses a built-in filter. When the filter needs replacing (becomes soiled or
defective), the measurement readings require a longer stabilization time. Please contact Extech
for replacement filters
Dew Point and Wet Bulb Temperature Measurements
1. Connect the Moisture probe to the jack at the top of the meter on the right
2. Switch the meter ON by pressing and holding the power button for 1.5 seconds
3. Press and hold the FUNCTION button to select the Wet Bulb or the Dew Point mode. When the
Dew Point mode is selected, the display icon dp is shown on the secondary display area. When
the Wet Bulb mode is selected, the display icon _et is shown on the secondary display area.
4. Carefully remove the protective cap from the moisture probe. The probe tip is extremely sharp,
use caution
5. Insert the probe tip into the material under test far enough to cover the sensor’s openings
6. The meter will now display the Dew Point Temperature or Wet Bulb Temperature on the primary
(upper) LCD digits. Use the Setup mode to change the temperature units of measure
