The ACI Transmitter Board Only Series features a two-wire, 4 to 20 mA loop powered output signal with optional 3-Wire voltage output signals available. Sensors are not included with the board only transmitter since they are designed to be used with any existing 100 or 1000 Ohm Platinum RTD sensor with a 385 temperature coefficient. All transmitters must be ordered with the temperature span that you require, since the boards are tuned to give you the best performance characteristics for the temperature span specialized. Zero and Span adjustments are available for recalibration in the field when using NIST Certified equipment. ACI recommends the use of an 18 to 22 AWG shielded cable for all temperature transmitter installations to protect against the introduction of noise onto the signal lines. ACI does over recalibration services for any transmitters sent back to us for a nominal fee.