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LB-710A - Industrial Thermometer & Hygrometer

LB-710A industrial thermometer, industrial hygrometer
  • functions: industrial thermometer, industrial hygrometer
  • measurement: temperature, relative air humidity
  • wide operating temperature range
  • double-wire connection
  • digital transmission of results over considerable distances
  • LCD display
  • temperature measurement resolution of 0.01°C
  • robust and dust-proof housing
  • optional measurement result:
    • dew point temperature
    • moisture content
    • relative humidity
  • computer software

Description of the thermometer/hygrometer

The LB-710A thermometer/hygrometer is designed for air temperature and relative humidity measurement in rooms. It may operate in extremely dusty rooms, thanks to the use of air-tight housing and suitable filter to protect the measuring sensors. It is a small, stationary device, powered by an external source. Measurement data are displayed on a two-row LCD display.

For the sake of performing measurements the instrument uses data from the external Pt-1000 temperature sensor and the relative humidity capacitive sensor. On the basis of the known non-linear characteristics of the temperature sensors and digital calibration data stored during calibration on the device storage memory, the instrument’s built-in microprocessor calculates the current relative humidity and temperature measurement results. The results are sent from the electronic thermo hygrometer in a digital form to the mother data collection system.

This professional thermometer/hygrometer is equipped with the LAB-EL S300 digital current interface, with runtimes analogues with the RS232C standard. Except for data transmission, this interface is used also to power the thermo hygrometer — to this end, a two-wire line (e.g. the type used in telephone installations) is used, with the provision that the polarity of interface wires connection is at the user’s discretion.

The thermo hygrometer may be connected to any given supervisory system, e.g. LB-722 climate regulator; LB-480, LB-489 or LB-476 hubs; LB-856 meter; LB-755 panel and (with the use of the LB-371 converter) to the RS232C interface, or (with the use of the LB-375 converter) to the USB interface of any PC thus establishing a monitoring system. It enables remote and automatic collection of measurement data from the industrial thermo hygrometer. The humidity measurement result may be presented in the accompanying PC software (that comes with LAB-EL instruments), with the use of other units: dew point temperature (in °C), moisture content (g/kg) or absolute humidity (kg/m3). The LB-710A industrial thermo hygrometer’s interface output is executed with screw clamps located inside the housing, to which a cable is introduced via an opening 7 mm in diameter.

This industrial thermometer (industrial thermo hygrometer) is equipped with a configuration jumper that when inserted enables the measurement results to be sent in a format compatible with the LB-710, and this makes it possible to connect a thermo hygrometer to devices and systems, which enable interaction with the LB-710A format.

The electronic thermometer/hygrometer does not feature mechanical calibration elements (e.g. potentiometers). The thermometer/hygrometer calibration includes sending calibration data via digital interface to the thermo hygrometer’s permanent storage, obtained from the calibrated climatic conditions. It ensures convenience and high calibration accuracy as well as the stability of the thermo hygrometer's metrological parameters over time.

The industrial thermometer (thermo hygrometer) may not be subject to direct atmospheric precipitation nor water vapour condensation, and so for use in open spaces (e.g. in a weather cage) the LB-710R version should be used.

The standard version of the industrial thermo hygrometer is fitted for short-term (up to a few hours) measurements within the measuring limits. In addition to measurements, the electronic thermo hygrometer should also be kept in the recommended continuous operating conditions. In the standard version, the industrial thermometer (thermo hygrometer) is equipped with a sensor screen (impurities filter), type F3.

Each thermometer/hygrometer, as per order, may feature an individual calibration certificate issued by LAB-EL Calibration Laboratory, by the Central Office of Measures in Warsaw or by the Military Metrology Centre in Zielonka.

The LB-710 thermometer/hygrometer earned an approval of RP T 95 77 type, awarded by the Chairman of the Central Office of Measures in Warsaw.

LB-710A thermometer/hygrometer — dedicated software

This device may additionally come with an advanced software for Windows — the LBX software — or for Linux — the PSM software — enabling:

  • presentation of current readings from devices;
  • alarm monitoring and signalling;
  • presentation of archived data — charts, reports, histograms;
  • data archive management;
  • access for remote clients.

For this thermo hygrometer, also the basic (simple) LB-710 software is available, enabling:

  • the presentation of current readings from the device;
  • saving measurement results in a file.

Technical Data

Measurement uncertainty ±0.1°C  ±1 final digit
Measurement range -40…+85°C  
Measurement uncertainty ±2.0% within the range of 10…90% ±1 final digit
±4.0% outside the range of 10…90%
Measurement range of LB-710 10…95% for temperatures up to +40°C
10…60% for temperatures up to +70°C
10…40% for temperatures up to +85°C
Measurement range of LB-710H 0…100% for temperatures up to +60°C
0…70% for temperatures up to +70°C
0…40% for temperatures up to +85°C
Parameter Reading range Resolution
Air temperature (industrial thermometer) -40.0…+85.0°C 0.01°C, optionally 0.1°C (configured with a jumper)
Relative humidity (industrial hygrometer) 0.0…99.9% 0.1%
Temperature range 0…40°C
Humidity range 20…80%

*) Exceeding the recommended continuous operating conditions for the industrial thermometer (e.g. when installing the device outdoors) requires the use of additional protective measures for the electronic part of the device against the eventuality of water entering the device (usage of additional external housing).

Voltage range 8…24 V DC  
Power consumption 2 mA average
25 mA maximum
External dimensions of the housing  170 x 64 x 35 mm   
Material plastics (polymas, ABS)  
Housing protection class IP 65 additionally limited by the protection class of the filter


Transmission parameters: time, according to RS232C, 300 bps, 7 information bits, without parity control, 1 stop bit operating in the standard of the so-called digital current loop.


industrial thermometer — C01 CONNECTIONC01 connection

By special order, the following set-ups are available:

  • LB-710AH — professional thermo hygrometer with the humidity measurement range extension to 0…100%, in comparison to the standard range;
  • LB-710AFn — version of sensors’ cover (according to description), the version is given if it is not F3;
  • LB-710AY — industrial thermometer/hygrometer with C01 connection (instead of clamps inside the cover).