AquaLab TDL

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Laser accuracy. Low-maintenance usage. Lightning fast measurement. The AQUALAB TDLstands alone, letting you measure water activity in previously impossible-to-measure samples.

SKU: H50270IN Category: Tags: ,


The volatility problem

AquaLab TDL answers the following problem: Measuring water activity in samples such as sauces, dressings, spices, or teas has traditionally been difficult. The reason: they contain volatile compounds that interfere with chilled mirror and capacitance sensors.

Laser speed. Laser accuracy. Laser simplicity.

As world experts in water activity, it wasn’t enough to engineer an instrument that directly measured water activity in most foods. So we created the TDL, which uses a laser sensor capable of accurately measuring even the most difficult volatiles. It’s easy to use and takes only minutes to measure any sample—even soy sauce, pure alcohol, and gasoline. The TDL delivers readings you can completely trust, no matter what the sample contains.

Cuts through the volatility problem with laser precision

When it comes to measuring water activity of volatiles, readings don’t get more precise. That’s because the TDL uses a laser tuned to the absorption band of water. The laser beam—less than one nanometer wide—locks on to water molecules no matter what the concentration of volatiles. The TDL is even able to correctly measure the water activity of pure alcohol.

Measuring volatile compounds has never been easy. Until now.

Despite being a complex instrument, the TDL is easy to use. Its sensor has no moving parts and is housed in a fully sealed sample chamber. Best of all, it doesn’t require user calibration. You’re five minutes away from an accurate water activity no matter what the sample is.

Accurate readings in only 5 minutes

The TDL’s laser takes five minutes to make a measurement of most samples. Compared to other instruments that take almost an hour, this adds up to significant time savings and quicker quality measurements no matter what ingredients are in your sample.

Volatility meets its match

Laser accuracy. Low-maintenance usage. Lightning fast measurement. The TDL stands alone, letting you measure water activity in previously impossible-to-measure samples.


  • Fast: water activity readings in about 2 minutes
  • Accurate:  ±0.005 aw
  • Accurately read any sample, including those with volatiles
  • Verifiable with independent salt standards
  • Repeatable: different users, different locations, same result
  • Portable: weighs just 7 pounds
  • Easy to use: precise aw readings with minimal training
  • Secure: offers administrative control over calibration and data



The METER Group core attributes are the features that define the brand. They are the substance from which we build industry-leading businesses in existing and new markets. Our core attributes are: 01 Scientific Expertise Maintaining the leading edge of measurement theory 02 Services Focusing on the needs of our customers 03 Engineering Creating innovative products, services, and systems 04 Design Communicating purpose and intent through details 05 Simplicity Reducing complexity 06 Precision Optimizing form and function  

Additional information

Weight3.1 kg
Dimensions26.7 × 17.8 × 12.7 cm
Sensor TypeTunable diode laser
Water Activity Accuracy±0.005 @ 25 ◦C
Water Activity Resolution0.0001 aw
Water Activity Range0.000 − 1.000 aw
Water Activity Repeatability0.001 aw
Read Time* 5 min
Temperature Control25 ◦C standard; 15 to 50 ◦C (with calibration)
Temperature Adjustment Increment1 ◦C
Sample Temperature Accuracy*±0.2 ◦C
Sample Temperature Resolution0.01 ◦C
Temperature StabilityUser-selectable range, internal thermoelectric controlled
Sample Dish Capacity7.5 ml recommended (15 ml full)
Measurement TimeAverage of 5 minutes
Program IdentificationAlphanumeric, programmable to display product name, lot, or product ID number
Data Storage8,000 readings
Data CommunicationsUSB
Display128 x 64 pixel graphical display with backlighting
Case Dimensions26.7 x 17.8 x 12.7 cm
Case MaterialMachined aluminum frame; Lustran 433 (ABS) with fire retardant
Weight3.1 Kg (6.83 lbs.); instrument only: 6.55lb = 2.97 kg
Power110 to 220 VAC, 50/60 Hz warranty: one year parts and labor
Operating Environment4 to 50 ◦C; 90% relative humidity (noncondensing)
WarrantyOne year parts and labor
*AQUALAB TDL is calibrated to a NIST traceable temperature standard.