Campbell 229 Specifications - page 2
Campbell Scientific, Inc.
|
815 W 1800 N
|
Logan, UT 84321-1784
|
(435) 227-9000
|
www.campbellsci.com
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Current Excitation Modules
Either a CE4 or CE8 current excitation module can provide a con-
stant current to the heating element of the 229. The CE4 sources
current for up to four 229s, and the CE8 sources current for up to
eight. Both modules require a 12 Vdc power source.
The number of 229 sensors measured by one datalogger can be
increased by connecting a CE4 or CE8 to one or more AM16/32-
series multiplexers
2
. Up to four multiplexers can be connected to
the CE4, and up to eight multiplexers can be connected to the CE8.
© 2003, 2013
Campbell Scientific, Inc.
July 19, 2013
2
The CE4 and CE8 modules switch currents that are greater than 30 mA, which degrades the contact surfaces of the mechanical relays.
Therefore the multiplexer channels to which the CE4 or CE8 have been connected may become unsuitable for other applications (refer to the
multiplexer manual for more information).
Ordering Information
The CE4 can source current for four 229 sensors directly.
The outputs of the CE4 can be connected to as many as
four multiplexers, greatly expanding system capacity.
The CE8 can source current for eight 229 sensors directly.
The outputs of the CE8 can be connected to as many as
eight multiplexers, greatly expanding system capacity.
Specifications
229 Water Matric Potential Sensor
Measurement Range: -10 kPa to -2500 kPa
Measurement Time: 30 s typical
Thermocouple Type: copper/constantan (type T)
Heater Resistance: ~34 Ω
Resolution: ~1 kPa at matric potentials < -100 kPa
Diameter: 1.5 cm (0.6 in)
Length: 6.0 cm (2.4 in)
Sensor Weight: 10 g (0.35 oz)
Cable Weight: ~23 g/m (0.25 oz/ft)
CE4/CE8 Current Excitation Modules
Output: 50 mA ±0.25 mA, regulated
Output Channels
CE4: 4
CE8: 8
Power: 12 Vdc source required
Active Current Drain:
25 mA + (50 mA) x (number of 229s connected to the CE4 or CE8)
Dimensions
CE4: 11.5 x 5.4 x 2.7 cm (4.5 x 2.1 x 1.1 in)
CE8: 16.5 x 5.4 x 2.7 cm (6.5 x 2.1 x 1.1 in)
Weight
CE4: 131 g (4.6 oz)
CE8: 184 g (6.5 oz)
Water Matric Potential Sensor
229-L
Heat Dissipation Matric Potential Sensor with user-specified lead
length. Enter lead length, in feet, after the -L. Recommended
length is 25, 50, 75, or 100 ft (8, 15, 23, or 31 m). Must choose a
cable termination option (see below).
Cable Termination Options (choose one)
-PT
Cable terminates in stripped and tinned leads for direct con-
nection to a datalogger/current excitation module terminals.
-PW
Cable terminates in a connector for attachment to a
prewired enclosure.
Current Excitation Modules (choose one)
CE4
Four-Channel Current Excitation Module
CE8
Eight-Channel Current Excitation Module
Cable for Current Excitation Modules
CABLE3CBL-L
22-AWG, three-conductor cable with user-specified lead
length. Enter lead length, in feet, after the -L. This cable
can be used to connect a CE4 or CE8 to the datalogger.