Deploying a long-term system

Instruments deployed outdoors for long periods of time are bound to experience a wide range of elements and challenges inherent to working in remote locations. While LI-COR instruments are intended to withstand rigorous field research, there are steps you can take to ensure your equipment continues to perform at its peak.

Protection from the elements

The LI-8250 Multiplexer, 8250-01 Extension Manifold, and the LI-870 CO2/H2O Analyzer are weatherproof. However, we do still recommend you take the conditions of your site into consideration. Some sites may require you to place these instruments on a pallet or other object to protect them from flooding or heavy snow events. Other sites may subject these instruments to significant solar loading. At these sites, the instruments may benefit from a cover to provide shade and ensure they remain within their operating temperature range.

The LI-78xx Trace Gas Analyzers are weather-resistant, but they are not weatherproof. For an LI-78xx Trace Gas Analyzer to be deployed in the field for extended periods, they must be covered and elevated. The cover can be something simple, such as a doghouse or pup tent.

Figure 2‑1. An example long-term system setup with an LI-78xx Trace Gas Analyzer, LI-8250 Multiplexer, and LI-870 CO2/H2O Analyzer.

Power requirements and consumption

A LI-8250 Multiplexer long-term system deployed in the field can be run on mains power using the outdoor AC to DC power supply (part number 8250-770) or on a user-supplied external DC power source, such as solar panels or a fuel cell.

Table 2‑1. Typical long-term system power consumption (Wi-Fi off) based on the number of chambers and additional consumption for the LI-870.
Chambers Extension Manifolds Idle (W) Active (W)
1 0 4.9 20.1
2 0 5.2 20.4
4 0 6.0 21.2
8 0 7.5 22.7
15 1 10.9 36.4
22 2 14.3 39.8
29 3 17.8 43.3
36 4 21.2 46.7
Additional for LI-870 5.0 5.0

The LI-8250 Multiplexer has three power supply options discussed in more detail in Powering the LI-8250 Multiplexer. The LI-870 CO2/H2O Analyzer is powered by the multiplexer as are each of the 8250-01 Extension Manifolds and 8200-104/C Long-Term Chambers. The Table 2‑1 shows typical power consumption based on the number of chambers, extension manifolds, and whether an LI-870 is included.

Each LI-78xx Trace Gas Analyzer requires its own connection to your power source. Either mains power of 100 to 240 VAC, using the universal power supply (part number 9968-232), or a user-supplied external DC power source of 10.5 to 33 VDC, using the auxiliary power supply adapter (part number 9968-242), will work.

Warning: The universal power supply (part number 9968-232) is not weatherized and should not be exposed to the elements. Using the universal power supply where it may become wet or damaged may shock the user or damage the Trace Gas Analyzer.

LI-78xx Trace Gas Analyzers include rechargeable lithium-ion batteries. These batteries should be installed even when connected to an external power source. The Table 2‑2 shows the power consumption for the LI-78xx Trace Gas Analyzers.

Table 2‑2. Power consumption for the LI-78xx Trace Gas Analyzers.
Steady state operation (W) Universal power supply during warmup (W) Auxiliary power supply during warmup (W)
22 Up to 100 with batteries charging Up to 65

For additional details on powering your LI-78xx Trace Gas Analyzer, see the instruction manual provided with your instrument. A complete copy of the manual can be found at