Water activity meter

Introduction

A water activity meter is an instrument used to measure the water activity of a product, which is the ratio of the vapor pressure of water in the product to the vapor pressure of pure water at the same temperature, and it is an important parameter that indicates the availability of water for microbial growth, chemical reactions, and physical changes, and it is used in the food, pharmaceutical, cosmetic, and agricultural industries for quality control, safety assessment, and shelf-life prediction. Water activity meters measure the water activity by determining the equilibrium relative humidity of the air in the headspace above the sample, using methods such as the chilled mirror dew point method, in which the sample is equilibrated in a sealed chamber and the dew point of the headspace air is measured with a cooled mirror, providing a fast and accurate measurement; the capacitance or resistive sensor method, which measures the relative humidity with a sensor; and the measurement is performed at a controlled temperature, and the water activity value, on a scale from 0 to 1, indicates the free water available in the product. Water activity is critical because it determines the growth of microorganisms, such as bacteria, yeast, and mold; it affects chemical reactions, such as browning and lipid oxidation; and it influences the texture, stability, and shelf life of products, and water activity meters are used for testing foods, such as baked goods, dried foods, meat, cheese, and confectionery; for pharmaceuticals and cosmetics; for agricultural products; and for research and development, and they are available as benchtop and portable instruments. With their importance in product safety and quality, water activity meters are essential instruments for the food and pharmaceutical industries.

Water Activity Meter with sensor LWAM-T2010

Water Activity Meter with Sensor is a single-point measurement unit with 0 to 0.980 aw of water activity (no condensing) measuring range and ± 0.015 aw measurement accuracy. The tempera...

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Water Activity Meter LWTM-T2010

Water Activity Meter is a real portable water activity meter, with a weight of only 1.5 kg, lighter than a mobile phone. It has 0 to 1.0 aw range and offers operating temperature range f...

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Standards

ISO 18787:2017-Foodstuffs-Determination of water activity

Complies with the above standards, but is not limited to them.

Features

1. Water activity meter for measuring water activity (aw) of foods and products.

2. Chilled mirror or resistive electrolytic sensor for accurate aw measurement.

3. Suitable for food, pharmaceutical, cosmetic, agricultural and quality control.

4. Includes measurement chamber, sensor, display, calibration standards and manual.

5. Supports product stability, shelf life, safety and quality assessment.

FAQ

Q1: What testing scenarios is this meter mainly applied to?

A: The water activity meter is used in food manufacturing, pharmaceutical production, cosmetic formulation, agricultural products, quality control and research to measure the water activity (aw) of products for stability, shelf life, microbial safety and quality assessment. It supports food product shelf life and stability testing, pharmaceutical product moisture and stability assessment, cosmetic product formulation and quality control, agricultural product storage and quality evaluation, intermediate moisture food development, and regulatory compliance for food safety. Water activity is a critical parameter affecting microbial growth, chemical stability, texture and shelf life of foods, pharmaceuticals and other products. It is essential for food, pharmaceutical, cosmetic, agricultural and quality control laboratories requiring water activity measurement for product stability, shelf life, microbial safety, formulation and regulatory compliance, where water activity (aw) is a critical parameter affecting microbial growth, chemical reactions, texture, moisture migration and shelf life of foods, pharmaceuticals, cosmetics and agricultural products, supporting product development, quality control, safety assessment and regulatory compliance in food, pharmaceutical and consumer product industries.

Q2: What standards does the meter comply with?

A: The water activity meter follows ISO 21807 for water activity determination, AOAC methods, ASTM standards, and relevant GB/T standards including GB 5009.238 for food water activity. The hardware complies with IEC 61010 laboratory safety standards. Calibration should use certified water activity reference standards (salt solutions) traceable to international standards.

Q3: What is the warranty period for the whole machine and key components?

A: The whole water activity meter is covered by a 12-month warranty. The sensor, measurement chamber, electronics and display are covered, while calibration standards, sample cups and fuses are consumables or accessories. Damage from improper use, sensor contamination or unauthorized repair is excluded. Extended service contracts are available for quality control equipment.

Q4: Is this device difficult to operate? Is professional training required?

A: Operation requires basic training in water activity measurement, sample handling and calibration. We provide an operation manual and remote guidance. Proper sample preparation, calibration, measurement technique and result interpretation are important for accurate water activity results, particularly for quality control and regulatory compliance.

Q5: What is the typical lead-time for order delivery?

A: Standard models require 7-30 working days. In-stock units can ship within 3-7 working days. Custom configurations or large built-to-order systems may require additional time, and we confirm the exact schedule before order confirmation.

Q6: Is regular calibration required? What is the recommended calibration cycle?

A: Calibration with certified salt solution standards recommended every 3-6 months for quality control use. Routine verification with a standard before each measurement session for critical testing. Sensor condition and cleanliness checked regularly. Sample cup condition verified. Full system performance verification annually.

Q7: Are supporting consumables universal?

A: Calibration standards, sample cups and filters are available from specialized suppliers, though instrument-specific parts should be verified. Long-term consumable cost is low to moderate depending on usage and calibration frequency.

Q8: Can I customize parameters or supporting accessories?

A: Customization includes sensor type (chilled mirror, resistive electrolytic), measurement range, sample chamber size, display language, data logging and communication. Additional sample cups, standards and accessories can be ordered separately. Custom orders extend delivery lead-time.

Q9: Does the purchase include on-site installation and commissioning service?

A: No complex installation is required. The package includes the water activity meter, calibration standards and instruction manual. On-site training service is available at additional cost for quality control setup.

Q10: What types of samples are compatible with this equipment?

A: The water activity meter measures water activity of solid, semi-solid, liquid and powder samples within the measurement range and sample chamber specification. Samples should be representative and at a consistent temperature. Very dry or very wet samples are within the aw range of 0 to 1.0. Volatile compounds in samples may affect certain sensor types. Users should calibrate with certified salt solutions before use, prepare representative samples, allow temperature equilibration, use clean sample cups, report results as aw with temperature specified, and follow applicable standard methods for sample preparation and measurement. For food safety, water activity results should be compared with regulatory limits for specific products (e.g., aw below 0.85 inhibits most pathogenic bacteria). The measurement chamber should be cleaned regularly to prevent cross-contamination between samples. For quality control, the meter should be calibrated and maintained per applicable food safety or pharmaceutical regulations, and results should be documented for traceability.