Features

Description

Laureate™ panel meters with the temperature signal conditioner board provide highly accurate, stable and repeatable temperature indication for multiple thermocouple types and 100 Ohm platinum RTDs. The meter accepts the outputs of types J, K, T, E, N, R and S thermocouples, plus 100 ohm platinum RTD’s with DIN alpha of 0.00385 and ANSI alpha of 0.003925. The thermocouple or RTD type, range and resolution (1° or 0.1°) are selectable from the front panel or via the serial interface. Display in Kelvin or Rankine can be selected by offsetting the Celsius or Fahrenheit range.

Cold junction compensation automatically corrects for temperature variations at the thermocouple reference junction at the meter. Open sensor indication is standard and may be set up to indicate either upscale or downscale. RTD excitation is provided by the meter. RTD connections can be of the 2-, 3- or 4-wire type. For 3- and 4-wire connections, the meter automatically compensates for lead resistance of the sensor.

All ranges for all temperature sensor types are digitally calibrated at the factory. This eliminates the need for field calibration or drift caused by potentiometers found in non-microcomputer based meters.

All Laureate meters allow exceptionally fast read rates. Concurrent Slope (Pat 5,262,780) is a method of analog-to-digital conversion that allows up to 60 conversions per second while integrating the input over a full power cycle. Fast read rates provide true readings and fast response for control applications. Display of peak value is standard.

Plug-in isolated analog output, dual-setpoint controller and RS-232/485 commu- nications or BCD output boards can upgrade the Laureate from stand-alone monitor to system interface and control. The Laureate temperature meter can serve as a highly accurate, isolated, 4-20 mA transmitter.

Laureate panel meters are available with a red or green LED display. Blanking of leading, non-significant zeros simplifies reading. The 1/8 DIN case is water tight to NEMA 4X (IP-65) from the front when mounted in the panel.

Specifications

Thermocouple Input

Pt 100 RTD Input

Thermocouple & RTD

The Laureate temperature meter allows 2-, 3- and 4-wire RTD hookup to the J5 connector. The meter applies an excitation current of 0.2 mA, which it monitors to make ratiometric corrections for excitation supply variations.

In 2-wire hookup, the meter senses the voltage drop across the 100 ohm RTD and both lead wires. The effect of the lead wires can be measured and subtracted by shorting out the RTD during meter setup.

In 3- and 4-wire hookup, the meter senses the voltage drop across the 100 ohm RTD and both lead wires as well as the voltage drop across the RTD and one lead wire. This allows it to determine the effect of one lead wire and mathematically subtract the effect of both lead wires.

Operation as a 4-20 mA Transmitter

With the optional analog output board, Laureate temperature meters can serve as superb, isolated 4-20 mA transmitters. The analog output is scaled to the display, which is linearized to ºC or ºF and is exceptionally accurate. The analog output further tracks the high read rate of the meter, at up to 60 readings per second at 60 Hz power. Fast update rates are beneficial in many closed-loop and PID control applications.

Operation as a Fast Controller

With the optional dual contact relay or dual solid state relay output board options, Laureate temperature meters can serve as extremely fast and accurate ON/OFF controllers for closed-loop temperature control.

Multiple setpoint operating modes are individually selectable for each relay, as explained in the dual-setpoint controller section. Relay duty cycles and chatter can be minimized with programmable hysteresis and time delays. High duty cycles and extremely fast response times are possible with the solid state relay, which has a typical response time of only 17 ms.

Operation as a Supervisory Monitor

By using the optional dual contact relay or dual solid state relay output options, Laureate temperature meters can monitor processes and provide alarms or shutoffs when these processes exceed normal limits.

A band deviation operating mode can be selected for each relay, where an alarm is generated whenever the reading is a selected number of counts above or below the setpoint. Relay operation can be selected as latching or non-latching. When an alarm or shutdown condition is reached, a latched output will remain in the alarm condition until it is reset by a front panel pushbutton, via the serial interface, or via the rear connector.