Process description 
test are as follows: 8:00 minutes before 20 ± 0.2 ° C (set the temperature and ambient temperature) water storage tanks into the solar water heater of the inlet, the water temperature when the water tanks imported export changes not in a specified time more than ± 1 ° C, the closure of solar water heater tank import, export valves.  Solar water heaters in the sunlight irradiation thermal storage, temperature recorded at this time as a solar water heater in the heat of the initial temperature.  Eight hours after the start circulating pump to solar water heaters inside temperature reaches uniform.  The temperature recorded at this time by weighing method and measured the water in the hot water tank volume calculated by the following formula solar water heaters in the heat.

　　 QS = PwCWVS (t2 - t1)

　　 Of which: QS-thermal energy storage tank in the volume of water contained in the VS system in the heat, unit MJ;
　　　　　 PW-water density, unit kg/m3;
　　　　　 CW-water heat capacity, unit J / kg. ℃;
　　　　　 VS-thermal energy storage tank in fluid volume, m3;
　　　　　 T2-end collector and style box is the hot water storage units ℃;
　　　　　 T1-collector test at the beginning of the inside temperature hot water storage units ℃;

　　 The trial for a separate day-long trial, the entire trial by such a test n components. Finally, solar water heaters, solar sites in different under illumination performance curve. Partial Test Device see figure 1.

 
 Figure 1 Test Device local chart 
The test system can be carried out eight thermal performance of solar water heaters, six of which can be law test, and the remaining two tests can be carried out drainage law.  The introduction of test methods for, drainage law principle of this paper (not quoted); test.

Second, measurement control system components
from the process, we can see the control of imported solar water heater temperature of 20 ± 0.2 ° C is very critical. Computer Control System used for this purpose. 。 Measurement and control system from Advantech PCI, PCL series card, ADAM4000 Series data acquisition module, communications module and the IPC bodies into, and used Advantech supporting configuration software Autoview and soft logic PC software Kingact achieve control and data logging and display function .  Measurement of parameters including temperature, solar radiation quantity, wind speed, flow; charged with objects including direct links valve, electric heater, inverter, pumps, solenoids, and so on.


　　 A control system in figure 2 below.

　　 PC operating systems to Windows 2000, the monitoring software can be run through the realization of real-time parameters of the scene, measurement, control, records, and gauge parameters emergency alarm and take corresponding measures.  IPC configuration software has a good man-machine interface, can be loaded as required different hardware drivers and shorten the development cycle of the project, to avoid the duplication of time-consuming hardware interface development work.

　　 As the pilot system to the requirements of high-precision temperature control, temperature sensors are used platinum resistance Pt100, in the whole operation of the system under calibration, according to the calibration data using least squares fitting of the data after the handover error is less than 0.05 ℃.  After the handover by the flowmeter calibration accuracy is superior to the quantitative way of inner-money ± 1%, 8 electromagnetic flowmeter largest error in a measurement error is 0.25%.