Application Background Printer Friendly Version
The rate of evaporation is defined as the amount of water evaporated from a unit surface area per unit of time. This parameter is an important indicator of the need for water of agricultural areas and also for hydrologists to monitor the water balance of an area.
Measuring the level of evaporation is especially important in mine sites, to determine the rate of improvement in water quality. All Unidata’s evaporation systems measure how much water evaporates from a US Class A evaporation pan by measuring the water level in an adjoining still well.
In agriculture people rather talk of evapotranspiration, meaning the combined evaporation of the soil and the transpiration of plants
Unidata supplies three models of evaporation system that cover nearly all evaporation measurement applications. Typically these systems are able to be used in dams and other water bodies, mines and remote installations, farms and pastoral leases, salt producers, fresh water producers and irrigation systems.
The simplest is a manually operated unit while the most sophisticated is automated to the point where it requires only infrequent intervention by an operator.
The more complex evapotranspiration monitoring can be performed on a site if weather parameters such as wind, relative humidity, temperate and solar radiation are available.
When these parameters are analysed as well, evapotranspiration can be determined by formulae such as Penman / Monteith.
Using a Stillwell reduces the impact of fluctuations in the pan’s water level caused by wind. The water level in the Stillwell is measured using a modified Model 6541 Water Level Instrument. This arrangement delivers measurements with a resolution of 0.2mm. An optional thermistor probe float assembly can be purchased separately. This assembly floats on the surface of the water in the evaporation pan to obtain a surface temperature reading.
The simplest model, known as the 6529-1 Evaporation Monitoring System, comprises of an evaporation pan with a bird and leaf cover and a manual measurement system.
These systems need a water supply which may be from a water tap, or from a tank on a tank stand.
If an underground tank/ water supply is used then water needs to be pumped from that supply to the system.
The 6529-2 Evaporation Recording System is similar to the 6529-1 but includes a precision water level instrument complete with a micrologger and an LCD display that shows the current depth of the evaporation pan.
The addition of the micrologger means that you can record evaporation measurements over time and have access to its other features such as SDI-12 communications, intelligent battery supervision, a modem interface and all the programmability found in STARLOG data loggers.
The 6529-3 is a fully automated system designed to operate for long periods without maintenance. In addition to the features of the 6529-2, it has the ability to automatically refill and discharge water from the evaporation pan. This enables you to manage a water source such as storing and recycling rainwater.
A water temperature sensor and a range of weather sensors can be added to help identify the relationship between evaporation and other site conditions. Typically these are required for evaporation and evapotranspiration studies and modeling.
You can also connect a Neon telemetry system to the system so you can monitor data acquisition, re-program the unit, and check the health of the site, all from a remote location. Landline, cellular, and radio communication links are supported. Using a Neon telemetry system decreases the need for time consuming site visits. Remember that when you use one of the telemetry options you will probably need to provide external power such as a solar panel, external battery, and regulator and use a larger enclosure.
|Options for Application Specific Instruments / Inputs||Unidata Part Number||Description|
|Evaporation Recording System-Manual||6529-1||Evaporation Recording System - Manual|
|Evaporation Recording System-Semiautomatic||6529-2||Evaporation Recording System - Semiautomatic|
|Evaporation Recording System-Automatic||6529-3||Evaporation Recording System - Automatic|
|Options for Neon Telemetry - NRT / RTU / Field Units||Unidata Part Number||Description|
|Cellular RTU 3G||2013F-AB03||Neon Metering Module 3G with Antenna and Li Battery|
|Cellular RTU 4G||2013F-AB04||Neon Metering Module 4G with Antenna and Li Battery|
|Cellular RTU 3G - Industrial||2016F-AB03||Neon Remote Terminal 3G with Antenna and Li Battery|
|Cellular RTU 4G - Industrial||2016F-AB04||Neon Remote Terminal 4G with Antenna and Li Battery|
|Low Earth Orbit Satellite Globalstar||2015E-AB0||Neon Remote Terminal - Satellite Globalstar Modem with Antenna and three Li Batteries|
|Ethernet||2017E-0B0-1 or 3||NRT Ethernet with single or triple Ethernet Ports|
with three Li Batteries
|Equatorial Orbit Satellite - Inmarsat||2018E-AB0-1 or 3||NRT Ethernet with single or triple Ethernet Ports|
with three Li Batteries
|LCD Display||2500E||NRT LCD Display|
|NRT Field Termination Strip||2103F||2015E,2016F,2017E, and 2018E NRT FTS|
|NRT Firmware Option||2303A-8M||8M Extended Memory Option|
|NRT Firmware Option||2303A-8M-CAM||8M Extended Memory & Serial Camera Option|
|NRT Firmware Option||2303A-CAM||Serial Camera Option|
|Options for Neon Application Software - Customer Server||Unidata Part Number||Description|
|Neon Application Software||2302A||Neon Server Software Licence Incl 5 NAL |
|Neon Application Software||2302A-10||Additional 10 NRT Access Licences|
|Neon Application Software||2302A-20||Additional 20 NRT Access Licences|
|Neon Application Software||2302A-50||Additional 50 NRT Access Licences|
|Options for Neon Application Software - Unidata Server||Unidata Part Number||Description|
|Neon Application Software||2301A||Neon Data Initial Subscription Setup Fee|
|Neon Hosting Service||2301A-01||Neon Data Service Fee for 1-50 NRTs|
|Neon Hosting Service||2301A-02||Neon Data Service Fee for 51-100 NRTs|
|Neon Hosting Service||2301A-10||Neon Data Service Fee Metering|
|Options for Conventional Dataloggers / Field Units||Unidata Part Number||Description|
|Standards Starlogger||6004D-11||Red Logger 512K with Alkaline Battery|
|Display Starlogger||6004D-21||Blue Logger 512K with LCD and Alkaline Battery|
|Prologger||7001D-11||Green Logger 1M with LCD and Alkaline Battery|
|Starlogger Field Termination Strip||6103E||6004D FTS|
|Prologger Field Termination Strip||7100E||7001D FTS|
|Starlog V4 Management Software||6308A-AUE||Starlog V4 Full Licence Key|