Specifications

CO2 measurements

Measurement range: 0 to 20,000 ppm

Accuracy

LI-850: Within 1.5% of reading

LI-830: Within 3% of reading

Calibration drift

Zero drift1: <0.15 ppm / °C

Span drift2: <0.03% / °C

Total drift at 370 ppm3: <0.4 ppm / °C

RMS noise at 370 ppm with 1 sec signal filtering: <1 ppm

Sensitivity to water vapor (LI-850 only): <0.1 ppm CO2 / mmol mol-1 H2O

Lower limit of detection: 1.5 ppm

H2O measurements (LI-850 only)

Measurement range: 0 to 60 mmol mol-1

Accuracy: Better than 1.5% of reading

Calibration drift

Drift at 0 mmol mol-1: <0.005 mmol mol-1 / °C

Span drift at 10 mmol mol-1: <0.006 mmol mol-1 / °C

Total drift at 10 mmol mol-1: <0.016 mmol mol-1 / °C

RMS noise at 10 mmol mol-1 with 1 sec signal filtering: <0.01 mmol mol-1

Sensitivity to CO2: <0.0001 mmol mol-1 H2O / ppm CO2

Lower limit of detection: 0.015 mmol mol-1

General

Output rate: Up to 2 measurements per second

Response time (T90)

CO2: <3.5 seconds from 0 to 375 ppm

H2O (LI-850 only): <3.5 seconds from 0 to 21 mmol mol-1

Measurement principle: Non-Dispersive Infrared

Traceability

CO2: Traceable gases to WMO standards from 0 to 3,000 ppm; traceable gases to EPA protocol gases from 3,000 to 20,000 ppm

H2O (LI-850 only): NIST traceable LI-610 Portable Dew Point Generator

Pressure compensation range: 50 to 110 kPa

Maximum gas flow rate: 1 liter min-1

Output signals: Two analog voltage (0 to 2.5 V or 0 to 5 V) and two current (4 to 20 mA)

Digital outputs: TTL (0 to 5 V) or Open Collector

DAC resolution: 16 bits across user-specified range

Power requirements

Input voltage: 12-30 VDC

After warmup (without pump): 0.33A @ 12 VDC (4.0 W) average

After warmup (with pump): 0.42A @ 12 VDC (5.0 W) average

During warmup: 1.2 A @ 12 VDC (14 W) maximum

Operating temperature range: -20 to 45 °C

Relative humidity range: 0 to 95% RH, Non-condensing

Dimensions: 22.23 cm W × 15.25 cm D × 7.62 cm H

Weight

No pump, no display: 1.0 kg

No pump, with display: 1.02 kg

With pump, no display: 1.3 kg

With pump, with display: 1.32 kg

Internal optical cell volume: 14.5 mL

Pump specifications (optional)

Operating temperature range: 5 to 45 °C

Storage temperature range: -20 to 60 °C

Operating humidity range: 0 to 80% RH

Nominal flow rate: 0.75 liters minute-1

Power consumption: 1 W (nominally)

Expected life span: 8,000 hrs in standard conditions with a normal load

Display specifications (optional)

Dimensions: 6.7 cm corner-to-corner

Resolution: 400 × 200 px; monochrome

Power consumption: <200 µW

Displayed variables: CO2 reading, H2O reading (LI-850 only), optical bench temperature, and pressure.

Dimensional drawings

Figure B‑1. All models of the LI-830 and LI-850 cases have the same dimensions.
Figure B‑2. Dimensions for the versions with no case. All dimensions in inches unless indicated otherwise.

Serial cable pin assignments

The image below shows the pin assignments for the 9-pin RS-232 serial connector.

Serial communication parameters

The LI-830 and LI-850 can communicate through a RS-232 serial port on the front of the instrument. You may need to set the communication parameters on your computer or your terminal emulator program. The RS-232 port is configured as Data Terminal Equipment (DTE) with no hardware handshaking. It is bi-directional, meaning information can be transferred both into and out of the instrument. The port is configured as follows:

  • Baud Rate: 9600 bps
  • Data Bits: 8
  • Parity: None
  • Stop Bits: 1
  • Flow Control: None

Specifications subject to change without notice.