Laurel Electronics LT2 RTD-to-4-20 DCmA & RS232/RS485 Transmitter

The Laurel Electronics LT2 RTD temperature transmitter and signal conditioner provides a linearized, highly accurate, stable and repeatable transmitter output for 100 ohm platinum, 10 ohm copper and 120 ohm nickel RTDs. Pt100 platinum RTDs can have a DIN alpha of 0.00385 or ANSI alpha of 0.00392. The 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 RTD type or as narrow as 150 counts (such as 15.0°), limited only by considerations of electrical noise and digital filtering time constants.

Digital calibration of all RTD ranges is performed 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. Typical accuracy for a Pt100 is better than ±0.04°C (±0.07°F) ±0.01% of reading. 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 changes in lead resistance to 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.

Features:

• 4-20 DCmA, 0-20 DCmA, 0-10 DCV or -10 to +10 DCV transmitter output, 16 bits, isolated
• RS232 or RS485 serial data output, Modbus or Laurel ASCII protocol, isolated
• Dual 120 mA solid state relays for alarm or control, isolated
• Factory calibrated for 100Ω platinum, 10Ω copper and 120Ω nickel RTDs
• 2, 3 or 4-wire RTD connection for lead resistance compensation
• User selectable input span from entire RTD range down to 15.0°
• Output update rate to 60/sec
• Analog output resolution 0.0015% of span (16 bits), accuracy ±0.02% of span
• Universal 85-264 ACV / 90-300 DCV or 10-48 DCV / 12-32 ACV power
• DIN rail mount housing only 22.5 mm wide, detachable screw-clamp connectors