Triplett LT68 Light Meter/Datalogger - High Range 400,000 Lux

Our review of the Triplett LT68 Light Meter/Datalogger finds it aimed at technicians, facility managers, and photographers who need a rugged, high-range instrument for precise illuminance checks. The LT68's single biggest reason to buy is its expansive measurement range up to 40,000 foot candles (400,000 Lux) combined with datalogging that automatically stores 16,000 readings, which makes it a practical choice for long-term surveys and compliance checks. In short, this review recommends the LT68 when you need both broad range and reliable logging without complicated setup.

Key Features

• High measurement range: Measures up to 40,000 ft-c (400,000 Lux) so it handles dim to very bright light sources without needing attenuation or multiple instruments.
• Spectral accuracy: The silicon photodiode and spectral response filter provide cosine and color corrected measurements for accurate readings from fluorescent, metal halide, high-pressure sodium, and incandescent sources.
• Datalogging capacity: Automatically stores up to 16,000 readings, making it suitable for long monitoring runs or batch measurement collection without frequent downloads.
• Useful display: Large backlit LCD with a 40-segment bar graph and data hold makes it easy to read measurements in dim or bright environments.
• Peak and relative modes: Peak mode captures fast transients down to 10 mS and Relative mode highlights changes in light levels for quick comparisons.

Who It's For

The LT68 is best for professionals who verify illumination for OSHA or facility standards in warehouses, parking lots, hospitals, schools, and industrial sites, and for photographers or lighting technicians who need a wide dynamic range and reliable logging. Its durable feature set and large display suit field use where visibility and quick data capture matter.

Less suitable for casual home users who only need occasional readings or very compact pocket meters; those users may prefer a simpler, lower-range meter without extensive datalogging. Also, users who need continuous live graphing to a PC should verify software compatibility and download options before purchase.

Pros & Cons

Pros

• Very wide measurement range up to 400,000 Lux covers almost any lighting situation.
• Large backlit display and 40-segment bar graph improve on-site readability and quick evaluation.
• Extensive datalogging (16,000 readings) and manual store/recall for flexible data collection.
• Peak and Relative modes capture transients and changes that matter in diagnostics.

Cons

• Not the smallest or simplest meter for occasional at-home use; its feature set targets professional applications.
• Users requiring integrated PC real-time plotting should confirm data export workflows, as the unit focuses on onboard storage.

Specifications

Model	LT68
Measurement range	Up to 40,000 ft-c / 400,000 Lux
Sensor type	Silicon photodiode with spectral response filter
Display	Large backlit LCD with 40-segment bar graph
Datalogging	Automatic up to 16,000 readings; manual store/recall up to 99
Modes	Peak (10 mS), Relative, Min/Max, Data Hold

Our Verdict

The Triplett LT68 is a strong choice for professionals who need a high-range, accurate light meter with substantial onboard storage and practical display features. It delivers good value for facility maintenance, compliance checks, and lighting diagnostics thanks to its broad range, cosine/color correction, and extensive datalogging capabilities.

Frequently Asked Questions

Can the LT68 measure different lamp types accurately?
The LT68 uses a silicon photodiode and spectral response filter to provide cosine and color corrected measurements for fluorescent, metal halide, high-pressure sodium, and incandescent sources.

How much data can the meter store automatically?
The datalogger can automatically store up to 16,000 readings and also supports manual store/recall of up to 99 readings on the unit.

Does the meter capture rapid light changes?
Yes, Peak mode captures the highest reading with a 10 mS response, and Relative mode highlights changes in light levels for comparisons.