SOLICITATION NOTICE
66 -- Multi-Chamber Soil Respiration System
- Notice Date
- 9/10/2007
- Notice Type
- Solicitation Notice
- NAICS
- 115310
— Support Activities for Forestry
- Contracting Office
- Department of Agriculture, Forest Service, Northern Research Station, 1992 Folwell Avenue - Acquisition Management, St. Paul, MN, 55108, UNITED STATES
- ZIP Code
- 00000
- Solicitation Number
- AG-63PX--P-07-0169
- Response Due
- 9/19/2007
- Archive Date
- 10/4/2007
- Small Business Set-Aside
- Total Small Business
- Description
- We request an 8-Chamber Multiplexed System for soil CO2 flux measurements. System components include the Analyzer Control Unit, Multiplexer, and Long-Term Chambers. The 8-Chamber Multiplexed System must be designed to take unattended, long-term, sequential soil CO2 measurements at up to 8 different locations and to investigate soil moisture, soil temperature, precipitation events, and photosynthetically active radiation that affect soil CO2 rates. The system must operate in temperature ranges from -20C to 45C allowing for a lengthy field season. The long term chambers must have a volume of 4.03 liters and cover 317 cm2 soil area; the chambers move away from the measurement area when not in use to minimize microclimate variability inside the collar. The required features for the 8-Chamber Multiplexed System: 1. Chamber pressure control. When the soil chamber is placed on the soil collar to take soil CO2 measurements, an increase in head-space pressure occurs. The increase in air pressure results in an artificial air-pressure gradient that reduces CO2 efflux out of soil into the chamber headspace. The result is an error in the measurement, and this error is very difficult to quantify. The specially designed vent function ensures that measured FCO2 accurately represents the rate occurring outside the chamber. 2. Good Mixing inside the chamber. Air movement in the head-space of a chamber can influence measured soil surface CO2 efflux rates by creating turbulence at the soil surface. This turbulence can increase measured efflux rates. However, it is also critical that air within the chamber be adequately mixed (homogenous) so that periodic (~every 5 seconds) sampling and analysis of head-space CO2 concentration accurately describe CO2 concentration in the whole chamber. 3. Multiple Chambers. Spatial variability in soil surface CO2 efflux is large, which requires an investigator to take multiple measurements. With the 8-chamber multiplexed system, timely spatial comparisons can be made over a large area to investigate heterogeneities within the soil subsurface. The rugged equipment design must allow for flexibility in the location of the soil CO2 measurements with minimal unnatural disturbance to the study area. 4. Leak test. It is essential to be able to test if the system is performing adequately after initial set-up and throughout the course of the study to ensure high quality date is produced. The associated software allows for a user controlled leak test of each chamber and a trouble shooting feature if a leak is detected. 5. Spectral interference. Both CO2 and H2O water absorb infra-red wavelengths of light. Traditional systems for measuring soil surface CO2 efflux have either ignored this interference or have developed and applied general corrections for H2O interference for an average water vapor content. Where general corrections are applied, error can still result especially as water vapor content diverges from the assumed average value (for example, after rain or prolonged drought). This problem would be solved if a soil respiration system could simultaneously measure both CO2 efflux and water vapor, such that each measurement is corrected for water vapor content of chamber head-space. 6. Exponential curve fitting. The initial CO2 increase rate is estimated based on exponential curve fitting to minimize the impact of the change in CO2 gradient inside the chamber on the flux measurement. 7. Multiple interfacing systems. The design needs to allow for flexibility in placement of the system in the field. Multiple interfacing tools are required to compliment the flexibility by allowing the system to be fully operated with a laptop, PDA or independently through an internal key-pad and CPU. 8. The government estimate is $35,000.00 to $40,000.00 9. Delivery ARO is 30 Days
- Place of Performance
- Address: USDA Forest Service, Northern Research Station, 1831 Highway 169 East, Grand Rapids, MN
- Zip Code: 55744
- Country: UNITED STATES
- Zip Code: 55744
- Record
- SN01400600-W 20070912/070910220200 (fbodaily.com)
- Source
-
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