Laboratory barometer LB-750 is designed for current atmospheric pressure measurement. The barometer works basing on three semiconductor pressure sensors. The application of three sensors in a barometer version LB-750B allows on: compensation of the individual sensor parameter scatter and detection of the emergency state in one of the sensors, what makes the device very reliable. When it comes to a barometer version LB-750W each one of the sensors is adapted for work in different scope of measurement (10..300..800..1200 hPa), what increases the measurement accuracy of the device in the whole scope.
The electric signal form the pressure sensors is measured by the analog-digital converter, and next it is tested in the microprocessor system of the barometer. Basing on the knowledge of pressure sensors characteristics conversion, the actual temperature of the pressure converters as well as the digital calibration data stored during the calibration process in the non volatile memory of the device, the microprocessor calculates the actual pressure measurement result. The measurement result is shown on the LCD screen.
The barometer has an option of the measurement result registry in the internal memory (version LB-750PR) - up to 4000 measurement points.
The measurement results are sent from the device in a digital form through a series interface "1" or "2", by which the barometer LB-750 can be attached to an outside supervisory system (i. e. concentrator LB-731, LB-473 or PC computer ). The interface "1" is used for calibration and programming of the barometer.
The device is equipped with a special program which allows on reading, through a PC computer interface RS232C, the actual and stored in the time function by the device the atmospheric pressure measurement results.
The barometer is made in a form of a panel casing ready to be hanged on the wall (see picture) or in a casing ready to be set on a table.
Barometers LB-750 can have an individual calibration certificate issued by the Air Force Technical Institute in Warsaw or the LAB-EL Calibration Laboratory.
|Measurement inaccuracy||+/- 0.4 hPa, +/- 1 last digit||version B|
|+/- 1.0 hPa, +/- 1 last digit||version W|
|Scope of measurement||700..1100 hPa||version B|
|10..1200 hPa||version W|
||+/- 0.1 hPa||version B|
|RECOMMENDED CONSTANT WORK CONDITIONS|
|Scope of temperatures
|Scope of humidity||20..80%|
|Level of environment corrosion aggressiveness accord. PN-71/H-04651||B|
|Degree of casing protection PN-92/E-08106||IP40|
Time and voltage transmission parameters: in accordance with RS-232 or RS-485 (optionally), 9600 bps, 8 information bits, without the evenness control, 1 stop bit.
Transmission time parameters: in accordance with RS-232, 300 bps, 7 information bits, without the evenness control, 1 stop bit : - output TXD - active state of TXD line answers current 25 mA, stand-by - 15 mA; output assures galvanic isolation, working in a standard called digital current loop