Cables used for traditional sensors such as pH and polarographic DO usually have dedicated wires for transmitting signals between the sensor and transmitter. The sensor signals are typically current, voltage, or resistance values representative of the measurement value. Hamilton electrical connections for traditional sensors include VP6, S7, S8, K8 (K9), and T82/D4. The opposite end of the cable is typically bare wire leads for connection to a transmitter. special versions of these cables are also available for connection to bioreactors.
Hamilton ARC and Visiferm DO sensors have built-in electronics within the sensor head. The electronics require a separate power supply to function, in addition to wires for signal transmission. 12 to 24V power supplied to the sensor depending on its source. If power is available at the process control system then the cable can be directly wired for power and signal using bare leads. These cables are referred to as Arc Data Cables.
In many cases, such as bioreactor controllers, there is no power available at the device. These applications require a power supply on a third leg of the cable, separate from the sensor or the device. The connector at the sensor will be a VP8 cable connector. If using a Wi2G BT wireless adapter, an M12-8 pole cable is needed in place of the VP8 cable. The connection at the opposite end can vary from either bare leads to specialized connectors such as BNC, Binder or Lemo depending on the controller manufacturer and their pin configuration.
Example - A powered cable such as Ref 355245-XX shown above has a VP connector for the sensor, a Lemo connector that works with certain bioreactors, and a 3rd leg with power supply that provides external power to the VisiFerm sensor.
Since external power for sensors is a common requirement of many bioreactor controllers Hamilton has developed a Bioreactor Cable Guide. Click below to learn more.