Precision Thermometer -200…+850°C with a resolution of up to 0.001°C — LB-499-PT

•   Pt100 (Pt1000) thermoresistors acting as temperature sensors
•   3/6 measuring channels (after integration in LB-480/LB-490)
•   Memory of calibration factors stored inside the probe plug
•   High resolution (0.001°C, 0.001 Ω)
•   Measurement uncertainty up to ±0.02°C
  
•   Internal auto-calibration circuits
•   Ease of use
•   Case made of robust materials
•   LBX software compatibility
•   Display
•   Customised Callendar-Van Dusen factors may be inputted
•   GSM, Ethernet, and USB interfaces (after integration in LB-480/LB-490)

Precision Thermometer Intended Use

The LB-499-PT is a module of a precision single-channel thermometer enabling temperature measurements within the range of -200…+850°C, with a measurement resolution of 0.01°C or 0.001°C. Practical measurement range will be additionally limited by the working temperature range, provided in the specifications of the external temperature sensor used.

In order to operate correctly, the LB-499-PT module must be integrated with one of the following devices:

• LB-480 — data recorder (1–3 individual modules),
• LB-490 — data recorder/weather station (1–6 individual modules).

The LB-499-PT module of the precision single-channel thermometer uses Pt100 or Pt1000 platinum thermoresistor as an external sensor protected by an appropriate sensor case (different execution options available). The module automatically recalculates resistance measurement results to temperature using Callendar-Van Dusen equation factors, according to PN-EN 60751 standard: Platinum sensors of industrial resistance thermometers and platinum temperature sensors.

In order to facilitate ease of use and avoid errors, when a probe with a thermometer resistor affixed to the LB-499-PT module of the precision single-channel thermometer is exchanged, the module reads calibration factors from permanent storage located in the measurement probe plug.

The calibration of the LB-499-PT module of the precision single-channel thermometer is performed by calibrating its measurement system with a known precision reference resistor (e.g. 100.000 Ω) and by entering the sensor calibration coefficients provided by the manufacturer or measured in a calibration laboratory. For standard calibration, the factors amount to:

• R0 = 100.000 Ω
• A  = 3.908 x 10^-3
• B  = -5.775 x 10^-7
• C  = -4.183 x 10^-12

The LB-499-PT module of the precision single-channel thermometer utilises a DB-9 female connection for connecting a four-wire external sensor and connecting the EEPROM with the sensor’s calibration data. All the module’s inputs are galvanically insulated and protected against overcharging — this, however, does not annul the obligation to follow the ESD protection principles.

In the LB-480 data recorder 1–3 LB-499-PT modules of the precision single-channel thermometer may be installed concurrently, thus creating a 1-, 2- or 3-channel precision thermometer. In the LB-490 data recorder 1–6 LB-499-PT modules of the precision single-channel thermometer may be installed concurrently, thus creating a 1- to 6-channel precision thermometer.

The results of the measured resistance and calculated temperature are stored in the memory of the LB-480 recorder or LB-490 recorder with a maximum frequency of 1 sps. The results may be averaged within a period of 1–10 seconds. The measurement results may be sent from the thermometer to external systems with the help of all the functionalities available in the LB-480 recorder or the LB-490 recorder (Ethernet, USB, GSM). The thermometer is compatible with SCADA LBX software, which enables archiving, visualising and signalling if the set values for measurement results are exceeded.

The external temperature sensor should be connected by means of a screened four-wire lead and with a screening lead connected to the sensor’s metal case, and properly connected in the LB-499-DB sensor’s plug, which eliminates any unfavourable electromagnetic interference with the measurement result. In order to take measures over a wide temperature range, or with extreme precision, special execution sensors have been designed with an appropriately long screen that eliminates temperature influence with the connection lead; they also feature a precision Pt100 wire thermoresistor — for example, the following sensors: TA-PL-100D, TA-PY-100D or TB-PL-100D (plus, the sensor’s screen dimensions, e.g.: 6x450). Other executions of the temperature measurement module sensors are possible after establishing the technical requirements.

Exemplary designation of a complete sensor for LB-499-PT inserts: LB-499-DB/TA-PL-100D-6x450.

Practical Applications of the Precision Thermometer

Applications of the LB-499-PT module of precision single-channel thermometer include:

• laboratory temperature measurements,
• thermometer calibration,
• thermostat operation control,
• automatics and remote measurement systems.

Technical Specifications of the Precision Thermometer

Temperature measurement resolution	Mode 1:  0.001°C, noise <±1 mK (averaging: 10 s)   Mode 2:  0.01°C, noise <±3 mK (averaging: 10 s)
Range of measured temperatures	-200°C … +850°C, additionally limited by the working temperature range of the external sensor
Range of measured resistances	0.000 Ω … 1,000.000 Ω   0.00 Ω … 10,000.00 Ω*
Temperature measurement uncertainty	≤0.02°C in the range of 0°C … 100°C (averaging: 10 s)  ±0.0004*(T-50°C) outside the range (additionally limited by the class of the external temperature sensor used, averaging: 10 s)
Measurement current	1 mA ±3% for Pt100 sensors   0.1 mA ±3% for Pt1000 sensors*
Input connection	DB9F
Input power	0.6 W (maximum)
Temperature range	storage: -10°C … +60°C usage: 10°C … 40°C, no condensation

Remarks: * The choice of Pt100 or Pt1000 sensor is possible at the stage of manufacturing a particular module. For better long-term stability it is recommended to use the Pt100 wire resistor sensor. The sensor should be connected by means of a screened four-wire lead with a screening lead connected to the sensor’s metal case, and properly connected with the sensor’s plug.