998-2821
Rev. D
Page 6
4) Connect the 4-20mA cable to the top of the Little Dipper
2.
5) Connect the Little Dipper
2 to the power supply and digital multimeter as shown
below.
Note: The power ground (Black Wire) and the 4-20 mA return (Brown Wire) are
not common. These wires should not be connected to the same point. Do not
allow the bare wires to touch each other or conductive surfaces. Use standard
electrical connection and insulation materials. Failure to properly connect the
Little Dipper 2 may result in damaged equipment.
2.3 Operation
Turner Designs’ Little Dipper
2 uses a Light Emitting Diode (LED) at a specific
wavelength to excite the fluorophore of interest in samples or source water. Upon
excitation, the fluorophore emits a different wavelength of light (fluorescence) that
will b
e detected by the fluorometer’s photodiode.
After power (8 - 30 VDC) is applied to the Little Dipper
2 allow 5 seconds for the
LED to stabilize. After 5 seconds measurements can be taken continuously as
current output (4
– 20 mA).
Multimeter
Common
20 mA
A
DC Power Supply
+
_
12 VDC
0.2 A
BLACK
BROWN
RED
ORANGE
Direction of
flow
When connecting the Little Dipper 2 to the cable,
pay special attention to the orientation of the pins.
Once the connection is made, slide the
collar down and rotate the collar to secure.
