CE4

The CE4 is a current-excitation module that applies a constant current to the heating element of up to four 229 Heat Dissipation Water Matric Potential Sensors. A current-excitation module is required when you use 229 sensors to measure soil water matric potential.

A CE4 current excitation module can provide a constant current to the heating element of the 229. The CE4 sources current for up to four 229s. The module requires a 12 Vdc power source. The number of 229 sensors measured by one data logger can be increased by connecting a CE4 to one or more AM16/32-series multiplexers. Up to four multiplexers can be connected to the CE4.

Note: The CE4 module switches currents that are greater than 30 mA, which degrades the contact surfaces of the mechanical relays. Therefore, the multiplexer channels to which the CE4 have been connected may become unsuitable for other applications. (Refer to the multiplexer manual for more information.)