Campbell Scientific AM16/32B 16- or 32-Channel Relay Multiplexer connects many sensors to single data logger (no cover)

Overview
The AM16/32B multiplexer significantly increases the number of sensors that you can measure with a Campbell Scientific data logger. It interfaces with the data logger and adds terminals so that you can wire additional sensors of almost any type.

Depending on sensor type, the AM16/32B can multiplex 16, 32, or 48 sensors. Up to six AM16/32Bs may be connected to the same data logger, depending on the number of control ports and analog inputs available.

The AM16/32B either multiplexes 16 groups of four lines (a total of 64 lines) through four common (COM) terminals. Alternatively, a manual switch setting allows the AM16/32B to multiplex 32 groups of two lines (also a total of 64 lines) through two COM terminals. A cable connects the common terminals to data logger analog inputs, excitation channels, or ground as required by the sensor. The data logger controls the multiplexer using two control ports, or one control port and one excitation channel.

Electrical Surge Protection
The equipment is protected from electrical surges using gas tubes on all inputs. A 35 V varistor is connected between the shield ground and ground lug to provide surge protection. The Reset, Clock, and +12 V terminals are protected by 18 V TVS diodes.

Benefits and Features
- Significantly increases the number of sensors the data logger can measure
- Can multiplex 16, 32, or 48 sensors
- Supports many types of sensors including thermistors, potentiometers, strain gages, vibrating wires, reflectometers, and soil moisture blocks
- Decreases the cost of cabling individual sensors on long wire runs
- Allows a relay address to be used to go directly to a specific channel—reducing power consumption and wear on the relay switches
- Electrical surge protection via gas tubes on all analog I/O, and varistors or TVS diodes on all other connections
- Prevents sensor-cable damage by providing strain relief for sensor leads and independent routing for sensor shield lines
- Eliminates the requirement for dc blocking capacitors for gypsum soil moisture blocks, significantly reducing sensor cost

Cover sold separately (see part number 19237).