The set is used for measurement and regulation of relative humidity and temperature in the rooms (i.e. warehouses, climate chambers) and signaling of alarm limits exceed.
The reading - control panel LB-722C receives from the attached to it
the relative humidity and temperature measurement results in a chosen
point of an object. Basing on it the panel LB-722C through one of 3
transmitter outputs realizes the following configuration functions:
The panel LB-722C registers in its memory the last 64 relative humidity or temperature results (configuration) in set 1 hour periods of time. The actual measurement results stored in the device's memory cover the last 64 hours and the device settings are shown on two four digit LED screens (digit height 12 mm). The screens can work independently in different work modes. In the basic mode the actual humidity and temperature measurement results are shown. When programming the device one of the screens shows a parameter being set and the other one an adequate description (symbolic parameter marking). A similar situation takes place when scrolling the memory, which contains the measurement results (in such case one of the screens shows – symbolically - time and the other one stored measurement result).
The remote control (programmer) LB-721 is a transmitter used for programming the panel LB-722C settings using an optical link (IR).The programmer LB-721 is a small, portable ("pocket") device, powered from one battery 9 V (6F22). It is equipped with eight key button membrane keyboard, which is very easy to read. Six of those key buttons switch the work mode of the servo's screens and the other two are used for increasing or decreasing a parameter when programming. The following are especially regulated:
The settings are stored in a panel's nonvolatile memory LB-722C (the values last chosen stay the same after the power supply is switched off).
The special way of programming the device by (using a special remote control) protects the settings from any change. It is impossible to make any unauthorized changes since there are no programming key buttons. The programmer’s work range is approximately1 m.
Thermometer - hygrometer
independent device equipped with a capacity relative humidity sensor
and a sensor Pt1000 used for temperature measurement. Thermometer –
has a microprocessor, which realizes measurement algorithms by taking
into consideration (non-linear) characteristics from both sensors as
well as calibration data stored in a nonvolatile memory. The
measurement results are transmitted to a panel LB-722C in a digital
form with the speed approx. 300 bods and a repetition period
approximately 2 s. The current interface used in the device powers the
measurement device. This type of solution guarantees simple
hytherograph - panel connection, using only two cables. Beside both
devices can be placed quite far from each other (distance limited by
the connection cable loop resistance - less than 100 ohm). Since the
transmission speed is quite slow and current interface standard, high
resistance to outside interferences using a cable of any type
characterizes the connection. The connection is resistant to changing
the cable endings (polarity).
During periodical calibration (confirmation) of the hytherograph LB-710 a two-way digital transmission is used. During calibration a set of coefficients grading the results gets stored in the nonvolatile memory of the hytherograph LB-710M. The regulation elements (potentiometers and trimmers) - that are often the source of problems (thermal instability, noises and clicks, random setting intervention etc.) were eliminated in such way.
Each thermometer - hygrometer (upon
a request) can have an individual
issued by the LAB-EL
or from the Central Army Metrology Center
in Zielonka. Thermometer – hygrometer
received the certification of type RP T 95
77 issued by the President of Central Measurement Office in Warsaw.
The panel LB-722C is equipped with a digital output, which transmits the actual temperature and humidity results with the speed of approximately 300 bps with time intervals approximately 2s. This output works in a standard similar to a hytherograph interface LB-710, what allows on simple creation of a computerized monitoring system of the environmental conditions in many rooms. Such system can include any number of hytherographs LB-710M as well as panels LB-720C.
A simple system with one or two hytherographs or servos can be obtained by connecting them to COM1 / COM2 computer ports through IBM-PC computer using conversion signal systems (current – voltage LB-371) produced by the LAB-EL company. Greater number of system elements can be attached using a concentrator LB-731 produced by the LAB-EL company.
The construction solution used in all devices assure obtaining wide scope of work temperatures (optionally in the M version - up to maximum -40..+70 °C). They also assure high reliability and resistance to interferences. All three devices ( LB-710, LB-722C, LB-721) were built basing on the microprocessors especially accustomed to work in such conditions. All plastics used in making the casings resist thermal risks at least in the scope of temperatures -40..+80°C.
|SCOPE OF WORK TEMPERATURES
|temperature||+/- 0.1 °C,
+/- 1 last digit
|humidity||+/- 2.0 %,
+/- 1 last digit
|in the scope of 10...90%|
|+/- 4.0 %,
+/- 1 last digit
|outside of the scope 10...90%|
|Regulation and alarm scope of regulation||humidity||0..99,9 %|
|Regulation levels hysteresis||+/- 0,5 %|
|RECOMMENDED CONSTANT WORK CONDITIONS *)|
|Scope of temperatures
|Scope of humidity||20..80%|
|Level of environment corrosion aggressiveness accord. PN-71/H-04651||B|
|Thermometer - hygrometer LB-710M||190 x 70 x 33 mm|
|Regulator LB-722C||180 x 130 x 106|
|Additional regulator casing LB-722C||308 x 255 x 160|
|Programmer LB-721||175 x 77 x 25|
|DEGREE OF RESISTANCE according to DIN40050|
|Thermometer - hygrometer LB-710||IP50|
|Panel LB-722||IP40 (standard) or IP54 (upon a special request )|
|CONTROL AND ALARM