1 Overview
FFZ-01Z type digital water evaporation station is made according to the People''s Republic of China Ministry of water conservancy and electric power "evaporation observation standards" SD265-88 and Chinese Meteorological Bureau in 2003 edition of "meteorological observation standard" requirements for automatic observation of water surface evaporation process.
Definition of "digital evaporation station" refers to the composition of the evaporation, evaporation station rain gauge and an overflow barrel, realizes the water surface evaporation observation station digital data acquisition and control process and replenishment process.
FFZ-01Z type evaporation station atmometer, pluviometer resolution is 0.1mm, overflow resolution of 0.025mm, with the highest level of relevant national standards, the precipitation and evaporation data form with the data storage processing requirements, can be used for water surface evaporation observation equipment of various types, instead of the manual observation is cumbersome and complex, automatic the observation and record of water surface evaporation.
The FFZ-01Z evaporation station can be connected with the GPRS data transmission device to form a telemetry station.
The equipment is limited to use in the non freezing period.
Atmometer and ombrometer, overflow barrel device of the equipment in the station shall be regularly maintained according to the requirements of specifications related products.

2 working principle
The evaporation station system by evaporation meter, rain gauge and overflow bucket as the basic observation tool, the collector automatic acquisition, processing and display of evaporation and precipitation, the overflow process information, automatic control, overflow bucket fill, evaporation and drainage process. The collector through the RS485/232 communication interface with the host computer system, data communication machine (RTU) connection, remote monitoring can be achieved by the water evaporation process information by using the application software system supporting the data processing and storage.
The evaporation tank water level of evaporation station should be kept on the water level mark line. In the absence of precipitation day, the collector automatically collects the water level changes in the evaporation bucket, and calculates the evaporation amount. When the height of the water evaporation barrels to the agreed value (water mark line 10mm), collector in the observation on the boundary (boundary for 8:00 moment hydrological, meteorological demarcation for 20:00) B3 to control water pump, automatic water evaporation, hydrosphere, the barrel water level recovery to the water line height, then. After the water with high as measuring points, evaporation rate measurement of the next time.
In rainy days, when the water level rises to the agreed value of evaporation (water mark line above 10 mm), the collector driven overflow pump B1, the evaporation of water into the bucket overflow bucket, bucket overflow when water level reaches the agreed value when the overflow end of the process, calculation of flow data acquisition after the start of the overflow bucket drainage pump B2, the overflow buckets of water discharged to the prescribed height of bottom water.
According to the "water surface evaporation observation standard" and the "surface meteorological observation specification" stipulated by the State Meteorological Administration, the calculation formula of evaporation amount is as follows:
Evaporation amount = (evaporation bucket water level measurement value of evaporation bucket water level initial value) + precipitation overflow flow
The upper form can be simplified as:
QF = (Wt-W0) +Qj-Qy
Formula: QF: represents evaporation of water surface, unit: mm
Wt: the water level of the evaporation bucket representing the measurement time (T): mm
W0: the evaporation bucket water level at the initial moment. Unit: mm
The Wt and W0 values are automatically measured by FFZ-01 digital water surface evaporation meter.
Qj said: the precipitation period is measured, the Qj value from the JFZ-01 digital gauge, unit: mm
Qy: to indicate the overflow in the measured period, and the Qy value is automatically measured by the overflow bucket. Unit: mm