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Micron Thermocouple & RTD
Temperature Panel Meter / Controller

High accuracy plus linearized transmitter & control outputs
CE Mark
  
UL Mark
RoHS Mark
Made in California

Standard Features

  • Input for thermocouple types J, K, T, E, N, R, S
  • Input for 100 ohm platinum RTDs with DIN and ANSI curves
  • Highly accurate and repeatable
  • Celsius, Fahrenheit, Kelvin or Rankine scales
  • Selectable 1º or 0.1º resolution
  • 2, 3 or 4-wire RTD connection with lead resistance compensation
  • Upscale or downscale open sensor indication
  • Up to 60 conversions per second
  • Peak or valley display
  • Green or red display
  • Universal AC power, 85-264 Vac
  • Options:
  • Low voltage power: 10-48 Vdc or 12-30 Vac
  • Dual or Quad relays: Form C contact or Form A solid state
  • Analog output: Isolated, 4-20 mA, 0-20 mA, 0-10V, -10 to +10V
  • Serial communications: RS232, RS485, Modbus RS485, USB, USB-to-RS485 converter
  • Certified to UL 61010C-1 (UL mark), EN 61010-1 (CE mark), and RoHS)

Description

Micron digital panel meters with a temperature signal conditioner board accept type J, K, T, E, N, R and S thermocouples, and 100 ohm platinum RTDs with a DIN alpha of 0.00385 or ANSI alpha of 0.00392. The thermocouple or RTD type, unit of measure (°C or °F), resolution (1° or 0.1°), and range 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 and RTD excitation are provided. Open sensor indication may be set up to indicate either upscale or downscale. RTD connections can be of the 2-, 3- or 4-wire type. With 3- or 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, with calibration factors stored in an EEPROM on the signal conditioner board. This allows temperatures sensors and signal conditioner boards to be changed in the field without recalibrating the meter.

Signal conditioner for Laureate Thermocouple & RTD Temperature MeterHigh read rates at up to 60 or 50 conversions per second while integrating the signal over a full power cycle are provided by Concurrent Slope (US Pat 5,262,780) analog-to-digital conversion. High read rates are ideal for peak or valley capture, real-time computer interface, and control. Peak and valley values are automatically captured. These may be displayed via a front panel pushbutton command or a control signal at the rear connector, or be transmitted as serial data.

Digital filtering is selectable for electrically noisy environments, including a batch averaging filter and an adaptive moving average filter which provides a choice of 8 time constants from 80 ms to 9.6 s. When a significant change in signal level occurs, that filter adapts by briefly switching to the shortest time to follow the change, then reverts back to the selected time constant. In a selectable Auto filter mode, the filter time constant is automatically selected based on detected signal noise.

Designed for flexibility. Plug-in isolated analog output, dual or quad setpoint controller, and serial communications boards can upgrade Microns from a simple monitor to system interface and control. Microns may be powered from 85-264 Vac or optionally from 12-30 Vac or 10-48 Vdc. They are available with red or green LEDs. The 1/8 DIN case meets NEMA 4X (IP65) specifications from the front when panel mounted. Any setup functions and front panel keys can be locked out for simplified usage and security.

SPECIFICATIONS

Thermocouple Input
TC Type
Range
Error at 25°C
.01% FS
J
-210°C to +760°C
-347°F to +1400°F
±0.09°C
±0.16°F
K
-244°C to +1372°C
-408°F to +2501°F
±0.1°C
±0.17°F
T
0°C to +400°C
-257°C to 0°C
+32°F to 752°F
-430°F to +32°F
±0.03°C
±0.2°C
±0.05°F
±0.36°F
E
-240°C to +1000°C
-400°F to +1830°F
±0.18°C
±0.32°F
N
-245°C to +1300°C
-410°F to +2370°F
±0.10°C
±0.17°F
R
-45°C to +1768°C
-49°F to +3214°F
±0.17°C
±0.31°F
S
-46°C to +1768°C
-51°F to +3213°F
±0.12°C
±0.22°F
  
Applicable to all thermocouple types
Calibration
Input resistance
Input current
Max lead resistance
Overall accuracy
Span tempco
Reference junction accuracy
Span tempco
Overvoltage protection
NMR at 50/60 Hz

CMR, DC-60 Hz
CMV, DC-60 Hz
Open sensor indication
NIST Monograph 125 (IPTS-68)
1 Gohm
100 pA
1 kohm max for rated accuracy
±0.01% of full span ±2 counts
±0.003% of reading/ºC
1ºC, 10ºC to 40ºC
±0.003% of reading/ºC
125 Vac
80 dB plus selectable digital filter
from 80 ms to 9.6 s time constant.
120 dB with 500 W imbalance
250 Vac from power and earth grounds.
Flashes full-scale.

PT 100 RTD Input

RTD Alpha
Range
Error at 25°C
.01% FS
DIN
.00385
-202°C to +850°C
-331°F to +1562°F
±0.03°C
±0.05°F
ANSI
.003925
-202°C to +631°C
-331°F to +1168°F
±0.04°C
±0.07°F
   
Applicable to all RTD types
Calibration, DIN
Calibration ANSI
Configuration
Excitation current
Overall accuracy
Span tempco
Zero tempco
Overvoltage protection
Open sensor indication
IEC 751 (IPTS-68)
NIST Monograph 126
2, 3 or 4-wire connection
0.2 mA
±0.01% of full span ±2 counts
±0.003% of reading/ºC
±0.03 deg/deg
125 Vac
Flashes full-scale
Sensor lead resistance tempco per conductor
2-wire, 10 mdeg/W/deg up to 10 W
3 & 4-wire, 10 mdeg/W/deg up to 100 W

Thermocouple & RTD Meters

Display
Readout
Color
Indicators
5 digits, 7-segment, 14.2 mm (.56")
Red or green LED
Minus sign, 2 red LED lamps
A-to-D Conversion
Technique
A-to-D Rate
Output Update
Display Update
Concurrent Slope™ (Pat 5,262,780)
60/s at 60 Hz, 50/s at 50 Hz
56/s at 60 Hz, 47/s at 50 Hz
3.5/s at 60 Hz, 3/s at 50 Hz
Power
Voltage, standard
Voltage, optional
Frequency
Power Isolation
85-264 Vac or 90-300 Vdc (DC operation not UL approved)
12-30 Vac or 10-48 Vdc
DC or 47-63 Hz
250V rms working, 2.3 kV rms per 1 min test
Excitation Output (standard)
5 Vdc
10 Vdc
24 Vdc
Output isolation
5 Vdc ±5%, 100 mA
10 Vdc ±5%, 120 mA
24 Vdc ±5%, 50 mA
50 Vdc to meter ground
Analog Output (optional)
Output levels
Current compliance
Voltage compliance
Scaling
Resolution
Isolation
4-20 mA, 0-20 mA, 0-10V, -10 to +10V (jumper selectable)
2 mA at 10V ( > 5 kOhm load)
12V at 20 mA ( < 600 Ohm load)
Zero and full scale adjustable from -99999 to +99999
16 bits (0.0015% of full scale)
250V rms working, 2.3 kV rms per 1 min test
Dual or Quad Contact Relay Outputs (optional)
Relay Type
Load Rating
Isolation
Form C, SPDT
8A at 250 Vac or 24 Vdc
250V rms working, 2.3 kV rms per 1 min test
Dual or Quad Solid State Relay Outputs (optional)
Relay Type
Load Rating
Isolation
Form A, SPST, normally open
130 mA at 140 Vac or 180 Vdc
250V rms working, 2.3 kV rms per 1 min test
Serial Data I/O (optional)
Board Selections
Protocols
Data Rates
Digital Addresses
Isolation
RS232, RS485, Modbus RS485, USB, USB-to-RS485 converter
Modbus RTU, Modbus ASCII, simpler Micron ASCII
300 to 19200 bps
247 (Modbus), 31 (Micron ASCII),
250V rms working, 2.3 kV rms per 1 min test
Environmental
Operating Temp.
Storage Temp.
Relative Humidity
Protection
0°C to 60°C
-40°C to 85°C
95% at 40°C, non-condensing
NEMA-4X (IP-65) when panel mounted

RTD Connections with Excitation & Lead Compensation

2-wire RTD connection to Laureate temperature panel meter

RTD hookup can be via 2, 3 or 4 wires to the J5 connector. The meter applies an excitation current of 196 μA for Pt 100, which it monitors to make ratiometric corrections for excitation supply variations.

In 2-wire hookup, the meter senses the combined voltage drop across the RTD and both lead wires. The voltage drop across the lead wires can be measured by shorting out the RTD during meter setup, and this voltage can then be subtracted from the combined total in software. However, the changing resistance of the lead wire due to ambient temperature changes will not be compensated.

In 4-wire hookup, the meter measures the voltage drop across the RTD directly via two sense leads, so that the IR drop across the two excitation leads is not a factor.

In 3-wire hookup, the meter senses the combined voltage drop across the RTD plus two excitation leads. It also senses the voltage drop across one excitation lead, and then subtracts twice this voltage from the combined total. This technique effectively subtracts all lead resistance and compensates for ambient temperature changes if the excitation leads are the same.

4-wire RTD connection to Laureate temperature panel meter

3-wire RTD connection to Laureate temperature panel meter

Application Examples

Linearized 4-20 mA transmitter output of Laureate temperature panel meter

Operation as a 4-20 mA Transmitter

With the optional analog output board, Micron 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.

Temperature controller operation of Laureate temperature panel meter Combined temperature controller and 4-20 mA transmitter operation of Laureate temperature panel meter

Operation as a Fast Controller

With the dual contact relay or dual solid state relay output board options, Micron 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, Micron 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.
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