Velleman DVM8855 - Manual (Page 5)

DVM8855
02/03/2009 © 2008 Velleman Components nv 5
• The °C/°F switch [L] is located inside the battery compartment under the battery. Move this switch
to the desired setting. The current setting is indicated [F] in the display.
• Also under the battery, there is a lock switch [M]. Move this switch to the ON-position for
continuous measurement. The current setting is indicated with a lock symbol [E] in the display.
Start measuring by pulling the measurement trigger [8] once. Consider disabling the laser targeting
beam in continuous measuring mode to save battery power. To stop and disable lock mode, set the
switch [M] back to the OFF-position. In lock mode, it is still possible to adjust EMS, HAL and LAL
values.
• The third switch under the battery is the alarm set switch [N]. Move this switch to the ON-position
to enable alarm warnings when high or low alarm limits are exceeded. When enabled, a Hi- and LOW
indication [I] are shown on the display.
• Close the battery cover [10] by pushing it back towards the device until it snaps in place.
• When the measured value exceeds a preset alarm limit, an audible alarm signal will be produced
(when the alarm set switch [N] is set to ON), and the according alarm icon in the display [I] will
flash. Alarm will stop when temperature is back within preset limits.
• Push the laser/backlight button [7] to cycle through the laser and backlight options (not available in
memory mode (LOG # displayed). Note that the laser beam is only an aiming aid, be careful when
using it. Refer to the safety instructions.
Push result
1 backlight on
2 backlight on and laser enabled
3 backlight off and laser enabled
4 backlight off and laser disabled
• To measure temperatures using the thermocouple, first connect the thermocouple to the bottom of
the grip [9]. The connector is slotted and can be inserted only one way. Do not force. Use the mode
button [6] to go to Tk mode [J] and read the thermocouple temperature [H].
• The DVM8855 has 20 memory locations to store measurements. Use the mode button [6] to go to
LOG mode [J] and use the up [5] or down [4] button to scroll through the memory. To store a
measured value, go to the desired memory location and press the laser/backlight button [7].
Emissivity measurement
• To determine the emissivity of a surface, go to EMS mode using the mode button [6]. Connect the
thermocouple and attach it to the surface. Pull and hold the measurement trigger [8] (consider
placing the meter in lock mode [M]). Press and hold the laser/backlight button [7] until the EMS
indication [J] starts flashing and the thermocouple measured value is shown [H]. Point the IR
sensor [1] towards the surface, close to the location of the thermocouple. When Tk and IR
measurements are identical and stable, press the up [5] or down [4] button. The measured
emissivity [C] is indicated [D] and normal measurement can be resumed.
Notes on emissivity measurement:
• Allow at least 15min for the thermocouple to reach the surface temperature.
• The measuring surface should be higher in temperature than the environment, e.g. 100°C surface
temperature will provide a more accurate measurement of the emissivity.
• When the temperature measured with the thermocouple differs from the one measured with the IR
sensor, or measuring points differ, the obtained emissivity will be wrong, or ERR is displayed.
• To exit emissivity measurement at any time, press the mode button [6].
General remarks:
• The device powers off automatically (after ± 7 seconds) when no activity is detected, unless it is
in lock mode.
• The unit will not measure correctly through transparent surfaces (e.g. glass), as it will measure the
surface temperature of the transparent surface.
• Steam, dust, smoke etc. will have a negative impact on the measurements accuracy.
• Measurements on shiny and/or polished surfaces are not recommended.
• To use the tripod, first plug the DVM8855 in the transmitter stand. Place the connector pins at
the front of grip [9] first, then tilt down until the meter snaps in place. To remove, lift the back
up first. Screw the tripod into the bottom of the transmitter stand and extend the legs of the
tripod to set the preferred height. Position the head and use the screw on the side to secure it.