Introduction
We are proud that we can present our system for monitoring temperature and humidity, which was developed at the request of the Ministry of Defence of the Republic of Croatian and to meet the requirements of technical equipment warehouses of military equipment of the armed forces of NATO members. Certainly, the use of the system can be much wider.
General
RTH system is used for measuring, monitoring and archiving of data on the temperature and humidity of air space in standard and explosive hazardous areas. It consists of RHT recorder apps for PC and connected sensors of temperature and humidity (RHT485, RHT485-D RHT CL EXi) and / or temperature sensor (TMP485, TMP485-D, TMP1W) perched in a controlled area. The system according to one communication port can be connected to the sensor 16 in any combination. Communication with sensors takes place via RS485 communication interface by up to 32 ports. RS485 ports can be local (USB converter) or remotely connected via a LAN or optical infrastructure (Ethernet/RS485, Optika/RS485 …) The complete system is the fruit of their own development and is based on the requirements of the Ministry of Defence as a system for monitoring the conditions of ventilation warehouse military equipment and expanded further development according to the requirements of other users of the system. With regard to its own development system can be tailored to the specifics of all the requirements of any user. In addition to visualization of measured data on a computer program takes care of the supervision limit values and the possible deviation alarms visual message on the computer screen and it is possible to upgrade and alerting via email, SMS, etc. Archiving of measured data is performed for each sensor according to the preset options ( time interval, changing values, …) into a Microsoft Access database that are so accessible and easily transferable to different users of the system.
RHT sensors
RHT sensor is a device that measure temperature and relative humidity of the room where the appliance is installed, and the information forwarded to the PC via RS485 communication interface.Temperature measurement range is from -40 ° C to +125 ° C while the relative humidity measured in the full range from 0 to 100%.Under normal conditions of use or RHT485 RHT485-D sensors while installation in potentially explosive atmospheres are used RHT CL EXi sensors (with additional equipment at each sensor). All HT devices are based on a digital sensor measuring the following characteristics:
| range of temperature measurement | -40°C do +125 °C |
| resolution of temperature measurements | 0,01°C (14 bit A / D conversion) |
| accuracy of the temperature measurement | 0,4 °C (kod 25°C) |
| Moisture measurement range. | 0 % do 100 % |
| Moisture measurements resolution . | 0,05 % (12 bit A / D conversion) |
| RH measurement accuracy | 1% |
RHT recorder application
The application is used to collect data from the RHT and TMP sensors and display and archiving of received measurements as well as to alert the user when the measured values are outside the desired area.
New Version RHT recorder application (in development) to monitor up to a total of 512 sensors placed at 32 locations (16 sensors per location).
In the top part of the form are:
- The list of active alarms in the system (showing all faulty conditions in a controlled system)
- Legend meanings given above coloring sensor fields
- Keys for “Confirmation alarm” generate “Report”
- The frame with the basic information of the selected sensors and chart the movement of measured values
The remainder of the form is filled metering data from connected sensors where each row corresponds to a location whose name is entered in the gray field at the start line and defines the location name (eg “Monitoring Center”, “Sljeme”, “Trogir” …). Showing only defined location and form of reduced height if less than 32 locations.At each location, we have switched to 16 (32) of sensors whose data are shown in the columns labeled as “zone 1″ to “Zona16″ (names can be user define). For each location will be shown as field sensor as defined by the location.
Depending on the type of sensor connected each field shows the current sensor data of the temperature and humidity in the case of HT sensors or only if the temperature sensor is connected to the TMP. Data are presented on a white background if the communication and measurement data within defined limits. Marked in red are sensors that do not communicate with a parent center. Blue and yellow are marked with sensors which is too low or too high ambient temperature.
The old version of the RHT recorder applications for monitoring up to 32 sensors per location
(two RS485 communication lines by 16 sensors)
RS485 communication
Communication computer with sensors is controlled via RS485 interface because it enables reliable communication in industrial environments up to a length of 1200m bus. Physically interconnect devices using twisted pair. To connect the local RS485 bus to the computer using the isolated USB/RS485 adapters while connecting to a remote location using Ethernet/RS485 or Optika/RS485 adapter.
