LI-7500 Data Sheet
LI-7500 Specifications
Type: Absolute, open-path, non-dispersive infrared gas analyzer.
Detector: Thermo-electrically cooled lead selenide.
Bandwidth: 5, 10, or 20 Hz, software selectable.
Path Length: 12.5 cm (4.72").
Operating Temperature Range: -25 to 50 °C (-40 to 50 °C verified optional range is also available).
User Interface: Windows® based software supports all setup, configuration and calibration functions through the RS-232 serial port.
Outputs: RS-232 (20 Hz Maximum)
SDM (>40Hz)
2 user scalable 16 bit DACs updated at 300 Hz.
Auxiliary Inputs: 2 channels for temperature and pressure sensors (during calibration).
Auxiliary Input with pressure sensor: 0-4.096V (±5V common mode rejection).
Power Requirements: 10.5 to 30 volts DC.
Power Consumption: 30 W during warm-up, 10 W in steady state.
Dimensions:
Head: Dia 6.5 cm, Length 30 cm. Designed for minimal wind flow disturbance.
Control Box: 35 cm x 30 cm x 15 cm (external dimensions).
IRGA cable: 3 meters (between sensor head and electronics control box).
Power, Serial, DAC, Auxiliary Input and SDM cables: 4 meters
Weight:
Head: 0.75 kg (1.65 lb.)
Control Box and Cables: 4.8 kg (10.5 lb.)
CO2 Color |
----- | µmol mol-1 | mmol m-3* | mg m-3* |
| Calibration Range | ----- | 0 - 3000 | 0 - 117 | 0 - 5148 |
| RMS noise** at ambient (370 ppm) | 0.08 | 0.0031 | 0.13 | |
| Zero drift with temperature (per °C) | Maximum Typical |
±0.3 ±0.1 |
±0.012 ±0.004 |
±0.5 ±0.2 |
| Gain drift with temperature at 370 ppm (% of reading per °C) |
Maximum Typical |
±0.1% ±0.02% |
±0.1% ±0.02% |
±0.1% ±0.02% |
| Direct sensitivity to H2O (mol CO2/mol H2O) | Maximum Typical |
±4.00E-05 ±2.00E-05 |
±4.00E-05 ±2.00E-05 |
±4.00E-05 ±2.00E-05 |
H2O |
----- | mmol mol-1 | mmol m-3* | g m-3* |
| Calibration Range | ----- | 0 - 60 | 0 - 2340 | 0 - 42 |
| RMS noise** in moist air (20 mmol mol-1) | 0.0034 | 0.13 | 0.0024 | |
| Zero drift with temperature (per °C) | Maximum Typical |
±0.05 ±0.03 |
±2 ±1 |
±0.04 ±0.02 |
| Gain drift with temperature at 20 mmol mol-1 (% of reading per °C) |
Maximum Typical |
±0.3% ±0.15% |
±0.3% ±0.15% |
±0.3% ±0.15% |
| Direct sensitivity to CO2 (mol H2O/mol CO2) |
Maximum
Typical |
±0.05 ±0.02 |
±0.05 ±0.02 |
±0.05 ±0.02 |
* at 25 °C, 98 kPa
** 5 Hz bandwidth, 10 Hz sampling