LI-250A Light Meter
Part Number: LI-250AProduct Details
Overview
• Direct Digital Readout: Instantaneous sensor output or 15-second averages can be shown on the LI-250A's display. Measurement units for any LI-COR sensor (µmol, lux, klux, or W/m²) are also displayed.
• High Quality Circuitry: The high quality amplifier in the LI-250A provides excellent long-term stability and automatic zeroing. This high gain amplifier gives very low input impedance to sensors, resulting in excellent linearity. Typical accuracy is 0.4% of reading at 25°C.
• Automatic Range Selection: The LI-250A simplifies operation by automatically selecting the range with the best accuracy and resolution for a given sensor input signal. The wide dynamic range allows measurements in a wide variety of light environments.
• Hold Key: Pressing the HOLD key lets you retain the current reading on the display. Pressing the HOLD key again returns the LI-250A to measurement mode where the display is continuously updated.
• Average Key: 15-second averages can be collected and then held on the display by pressing the AVG key.
• Hand-held, Battery Operated: The LI-250A's low power consumption gives you more than 150 hours of operation from a single 9-volt transistor battery. To conserve battery life, the meter auto-matically shuts off after 20 minutes of inactivity.
• Weathertight: The LI-250A case is O-ring sealed to make it weathertight.
• Sensor Calibration: Calibration multipliers for LI-COR sensors can be entered by simply pressing the CAL key, setting the display units (UNITS key), and then changing the sensor calibration multiplier with the up and down arrow keys. Two sensor multipliers can be held in memory to aid in switching between sensors.
Specifications
| Part Number: |
LI-250A |
| Accuracy - 0°C-55°C |
Typically ±0.6% of reading ±3 counts on the least significant digit displayed (all ranges) |
| Accuracy - 25°C |
Typically ±0.4% of reading ±3 counts on the least significant digit displayed (all ranges) |
| Battery Life |
150 hours typical with continuous operation |
| Display |
4½ digit LCD display. Updated every 0.5 seconds in instantaneous mode. |
| Keypad |
Sealed, 5-key tactile response keypad |
| Linearity |
±0.05% |
| Low Battery Detection |
Low battery indicator displayed with approximately 20 hours battery life remaining |
| Operating Conditions |
0°C to 55°C, 0 to 95% RH (non-condensing) |
| Power Requirement |
One 9V Eveready Alkaline #522 or equivalent (LI-COR part number 216) |
| Range Selection |
Autoranging (3 ranges) |
| Sensor Calibration |
Each sensor is supplied with a calibration multiplier. Calibration multipliers for two sensors can be stored in memory. Calibration multipliers are entered from the keypad. |
| Sensors |
Any LI-COR type "SA" or type "SB" sensor with BNC connector; Quantum, Pyranometer, or Photometric. Older LI-COR radiation sensors, or those without any connector must have a BNC connector installed. |
| Signal Averaging |
Sensor output can be collected and displayed as a 15-second average (approximately 60 readings). Averages are retained on the display in HOLD mode. |
| Size |
14cm × 7.7cm × 3.8cm D (5.5" × 3" × 1.5") |
| Storage Conditions |
-55°C to 60°C, 0 to 95% RH (non-condensing) |
| Warranty |
1 year parts and labor |
| Weight |
0.26kg (0.57 lbs) |