LI-1400 Datalogger Specifications

Current Inputs: Five channels; three through external sealed BNC connectors, and two through the 1400-301 Standard Terminal Block.

Voltage Inputs: Four high impedance (>500M ohm) single-ended channels accessed through the 1400-301 Terminal Block.

Pulse Counting Input: One pulse counting channel. Switch closure for tipping bucket rain gauge (1 Hz maximum).

Math Channels: 9 math channels. Math channels combine results of two channels with addition, subtraction, multiplication and division operators. Other math channel functions include fifth order polynomial, Steinhart-Hart function for thermistors, natural log, saturation vapor pressure, and dew point. Five math libraries are available to store commonly used functions.

Analog-to-digital Converter:

Resolution: 16 bit (1 part in 65,536).
Scanning Speed: 10 channels per second.
Voltage Accuracy: < 0.15% of full scale reading (25 °C). ± 0.2% (0 to 55 °C).
Current Accuracy: ± 0.3% of full scale reading (25 °C). ± 0.5% (0 to 55 °C).
Temperature Coefficient: ± 0.01% of reading per °C.
Linearity: 0.07%.
Frequency Rejection: >90 dB at 50 or 60 Hz (software selectable).

Input Noise (25 °C)

	Typical	Maximum
Voltage	± 76 µV	± 152 µV
Current	± 7.6 picoamps	± 30.4 picoamps

Voltage Range (Channels V1-V4):

Voltage Range	Resolution
± 2.5 volts	76 microvolts

Current Range Selection: Autoranging.

Current Ranges	Resolution
1 ± 250 nanoamps	7.6 picoamps
2 ± 2.5 microamps	76 picoamps
3 ± 25 microamps	760 picoamps
4 ± 250 microamps	7.6 nanoamps

Typical Resolution with LI-COR radiation sensors (Range 1)

LI-190	.0015 µmole sec-1 m-2
LI-200	.0001 watts m-2
LI-210	.025 lux

Current Channel Input Impedance: Typically < 0.03 ohm for ranges 1, 2, or 3; < 0.3 ohm for range 4.

Voltage Channel Input Impedance: >500M ohm on voltage channels V1 through V4. 100K ohm for current channels I4 and I5, when configured for voltage input.

D.C. Voltage Excitation: Two regulated: + 5.0 V ± 0.2% at 3 mA; Two unregulated: 9.5V ±10% or higher at 6mA. With external 14V input, unregulated output is ±13.4V.

Logging Periods: Seconds: 1, 5, 15, 30. Minutes: 1, 5, 15, 30. Hours: 1, 3, 6, 12, 24.

Sampling Interval: Seconds: 1, 5, 15, 30. Minutes: 1, 5, 15, 30, 60.

Short Term Averaging: Selectable at 1, 5, 15, or 30 seconds. While averaging, the oldest point is dropped when the newest point is added. Averaged readings reduce instrument noise by approximately the square root of the number of samples.

Keyboard: Sealed, 24-key tactile response keypad.

Display: Two line, 16 character alphanumeric LCD. Updated once per second. Temperature compensated readability from -15 to 55 °C.

Real Time Clock: Year, month, day, hour, minute, seconds.

Accuracy: ± 3 minutes per month (25 °C).

Internal Memory: 96K bytes available for data storage.

Program Memory: Stored in Flash memory for easy upgrades via the RS-232 port.

Communications: RS-232, hardwired Data Terminal Equipment (DTE) through 9-pin port. Baud rates are software selectable at 300, 1200, 2400, 4800 and 9600. Communication is bi-directional.

Battery Requirements: Four Alkaline "AA" batteries in sealed battery compartment.

Back-up Battery: Internal lithium battery maintains memory up to seven years.

Battery Voltage: Automatic low battery instrument shut-off. Remaining power after shut-off maintains data stored in memory. Low battery warning displayed before automatic shut-off. Power management software also shuts off the instrument after 15 minutes of inactivity.

Battery Capacity with "AA" Batteries: 60 hours continuous operation.

External DC Power: 7-16 VDC.

Case: ABS plastic case for splash resistant operation and protection from wind blown dust. Equivalent to an IP54 level.

Operating Conditions: -25 to 55 °C; 0 to 95% RH, non-condensing.

Storage Conditions: -30 to 60 °C; 0 to 95% RH, non-condensing.

Size: 22L x 13W x 4.3 cm D (8.6 x 5.1 x 1.7”). 9.3 cm (3.7") width of the lower case allows easy hand-held operation.

Weight: 0.7 kg (1.5 lb).