4-20 mA Current Output Transmitter
for Thermocouple & RTD Temperature

Features

• Input for thermocouple types J, K, T, E, N, R, S
• Input for 100 ohm platinum RTDs with DIN and ANSI curves
• 2, 3 or 4-wire RTD connection with lead resistance compensation
• Upscale or downscale open sensor indication
• User selectable spans from entire TC or RTD range down to 15.0°
• Output update rate to 60/sec
• Output resolution:  0.0015% of span (16 bits)
• Switching power supply for 85-264 Vac
• Easy setup with PC-based Instrument Setup Software
• DIN rail mount housing only 22.5 mm wide
• Detachable screw-clamp connectors
• Dual solid state relays for alarm or control, isolated
• RS232 or RS485 serial communications, isolated
• Universal AC power, 85-264 Vac
• Priced Reasonably (basic temperature transmitter)
  Options:
• Low voltage power, 10-48 Vdc or 12-30 Vac

Description

The Micron 4-20 mA transmitter provides a linearized, highly accurate, stable and repeatable transmitter output for multiple thermocouple types and 100 Ohm platinum RTDs. The transmitter accepts the outputs of types J, K, T, E, N, R or S thermocouples, plus 100 ohm platinum RTD’s with DIN alpha of 0.00385 or ANSI alpha of 0.00392. The thermocouple or RTD type and temperature range, specified in °C or °F, are user-selectable. The temperature range can be as wide as the entire span of the thermocouple or RTD type, or as narrow as 150 counts (such as 15.0°), limited only by considerations of electrical noise and digital filtering time constants.

All ranges for all temperature sensor types are digitally calibrated at the factory, with calibration data stored in EEPROM on the signal conditioner board.  This allows signal conditioner boards and ranges to be changed in the field with no need for recalibration. Cold junction compensation automatically corrects for temperature variations at the thermocouple reference junction at the transmitter. Open sensor indication is standard and may be set up to indicate either upscale or downscale. RTD excitation is provided by the transmitter. RTD connections can be of the 2-, 3- or 4-wire type. With 3- and 4-wire connections, the transmitter automatically compensates for lead resistance of the sensor.

Fast read rate at up to 50 or 60 conversions per second while integrating the signal over a full power line cycle is provided by Concurrent Slope (Pat 5,262,780) analog-to-digital conversion. High read rate is ideal for peak or valley capture and for real-time computer interface and control.

Three analog transmitter settings are jumper selectable: 4-20 mA, 0-20 mA or 0-10V. All selections provide 16-bit (0.0015%) resolution of output span and 0.02% output accuracy. The output tracks the reading from -99,999 to +99,999 counts that would be transmitted digitally. For DC signals, this reading has a rated accuracy of ±0.01% of full scale input and can be scaled in software. Output isolation from signal and power grounds eliminates potential ground loop problems. The supply can drive 20 mA into a 500 ohm (or lower) load for 10V compliance, or 10V into a 5K ohm (or higher) load for 2 mA compliance.

Standard features of Micron transmitters include:

• Analog transmitter output, 16-bit, user scalable and isolated. User selectable 4-20 mA, 0-20 mA or 0-10V levels.
• Serial communications, isolated. User selectable RS232 or RS485, half or full duplex, Modbus or Micron ASCII protocol.
• Dual solid state relays for control or alarm, isolated. Rated 120 mA at 130 Vac or 170 Vdc.
• Transducer excitation output, isolated. User selectable 5V@100 mA, 10V@120 mA or 24V@50 mA.
• Universal AC power supply for 85-264 Vac.

Easy Transmitter programming is via Micron's Instrument Setup Software, which runs on a PC under MS Windows. This software can be downloaded from this website at no charge. The required transmitter-to-PC interface cable is available from Micron (P/N CBL04).

Specifications

Micron 4-20 mA Transmitter for Thermocouple & RTD Temperature

Pinouts
Micron 4-20 mA Transmitter for Thermocouple & RTD Temperature