The PCE-WAM 20 Water Activity Meter is a high-precision portable aw meter designed for food and beverage QA/QC, product development, pharmaceutical testing, cosmetics, animal feed, research and laboratory applications.
The PCE-WAM 20 measures water activity from 0.0000 to 1.0000 aw with 0.0001 aw resolution and ±0.015 aw accuracy from 10 to 30°C, providing substantially greater measurement resolution than entry-level portable water activity meters.
Measurements can typically be completed in approximately 3 to 5 minutes. Three measurement modes, 1- to 4-point calibration, a 2.8-inch colour TFT display, internal storage for up to 5,030 measurement records and USB-C data transfer make the WAM 20 a strong choice for production QA/QC and laboratory users who need more precision, traceability and data management.
Water activity (aw) describes the amount of water in a product that is available to support microbial growth and participate in chemical, enzymatic and physical processes.
Water activity is expressed on a scale from approximately 0.0000 to 1.0000 aw, with pure water approaching 1.0000 aw under defined conditions.
Measuring water activity can help manufacturers and laboratories evaluate microbial stability, shelf-life behaviour, formulation consistency, drying processes, ingredient changes and production quality.
Moisture content measures the total amount of water present in a product.
Water activity describes how available that water is. Two samples can have similar total moisture content while having different water activity values and therefore different microbial, chemical or physical stability.
One of the biggest advantages of the PCE-WAM 20 over entry-level water activity meters is its 0.0001 aw resolution.
This allows the meter to display substantially smaller changes in water activity, making it useful for:
Display resolution should not be confused with measurement accuracy. The PCE-WAM 20 has a published accuracy of ±0.015 aw within the 10 to 30°C temperature range.
PCE specifies a typical water activity measurement time of approximately 3 to 5 minutes.
Faster measurements can be particularly useful in production QA/QC environments where multiple ingredient, in-process or finished-product samples must be tested during a shift.
Actual stabilization time may vary depending on the product, sample preparation, temperature and selected measurement mode.
The PCE-WAM 20 provides three measurement modes so users can adapt the instrument to different testing requirements.
Normal mode is suited to routine water activity measurements where the instrument is allowed to determine the sample value under its standard measurement procedure.
Fast mode is designed for applications where obtaining a result quickly is important, making it useful for routine production checks and screening measurements.
Continuous display mode allows the user to observe changes in water activity over time rather than relying only on a single final measurement.
This can be useful when investigating sample behaviour, stabilization or changes during method development.
The PCE-WAM 20 supports one-, two-, three- or four-point calibration.
Multi-point calibration allows laboratories to verify instrument response across a broader portion of the water activity range instead of relying on a single reference point.
Cambridge supplies Water Activity Standards at multiple reference values for calibration checks and routine instrument verification.
For routine QA/QC, consider calibration or verification standards that bracket the range of the products you normally test. For example, a laboratory routinely testing products around 0.60–0.80 aw may benefit more from reference points surrounding that range than from relying only on a reference near 1.00 aw.
The PCE-WAM 20 is particularly well suited to food production QA/QC because it combines higher resolution, fast testing, multi-point calibration and onboard data storage in a portable instrument.
Potential food and beverage applications include:
Water activity can be used to support product specifications and process monitoring, but the acceptable aw value must be established for the specific product and process.
Water activity is one of the intrinsic characteristics that can affect whether microorganisms are able to grow in a food.
The Canadian Food Inspection Agency notes that most pathogens will not grow when water activity is below approximately 0.85 aw. However, different microorganisms have different minimum water activity requirements and some yeasts and moulds can tolerate lower values.
A measurement below 0.85 aw should not automatically be interpreted as proof that a food is shelf stable or safe. Product formulation, pH, processing, packaging, storage conditions, microorganisms of concern and applicable regulatory requirements must also be considered.
Water activity is valuable during product development because changes in ingredients or processing can alter available water even when overall moisture content changes very little.
The PCE-WAM 20 can help R&D teams compare:
Its 0.0001 aw resolution is particularly useful where relatively small differences between formulations or batches need to be observed.
Water activity is one component of a shelf-life study and should be evaluated together with microbiological, chemical, physical and sensory information appropriate to the product.
PCE identifies pharmaceutical manufacturing and research among the applications for the PCE-WAM 20.
Water activity can be useful when evaluating suitable powders, tablets, capsules, ingredients and other formulations where available water influences microbial stability or physical characteristics.
Laboratories performing regulated or compendial testing should confirm that the instrument, calibration procedure, documentation and method meet the requirements of their specific quality system.
Water activity can also provide useful formulation information for suitable cosmetic and personal-care products.
Depending on the formulation, potential samples may include:
Water activity does not replace required microbiological testing or product-specific preservation studies, but it can provide additional information about the availability of water within a formulation.
PCE also identifies animal-feed production as an application for the WAM 20.
The instrument can be considered for suitable:
Water activity can complement conventional moisture-content testing by providing information about how available the water within the material is.
The PCE-WAM 20 simultaneously measures sample temperature from -10 to 50°C with 0.01°C resolution and ±0.1°C accuracy.
Temperature information is important because water activity is temperature dependent. Meaningful comparisons should therefore be made under stable and comparable temperature conditions whenever possible.
PCE specifies the ±0.015 aw accuracy within a sample-temperature range of 10 to 30°C. The instrument can display temperatures outside this range, but do not assume that the same ±0.015 aw specification applies outside PCE's stated temperature conditions.
The PCE-WAM 20 stores up to 5,030 measurement records internally.
This is a major advantage over basic water activity meters for production and R&D environments where many samples are measured over time.
Stored results can support:
The PCE-WAM 20 includes a USB-C interface for transferring measurement data to a computer.
PC software is available from PCE's download area and allows users to work with exported measurement data outside the instrument.
A USB-C cable is included with the meter.
A 2.8-inch TFT colour display provides a clear interface for measurement results, settings, calibration and stored data.
Menu languages include English, French, Spanish and Chinese, making the unit useful in multilingual laboratory and production environments.
The PCE-WAM 20 can be powered from four AA batteries or 5 V USB.
Battery operation and the supplied transport case make it possible to move the instrument between laboratory, QA/QC and production areas rather than permanently installing it at one testing station.
The aw sensor is connected to the instrument by an approximately 1.8 m cable, allowing the sample holder to be positioned conveniently during testing.
Consistent sample preparation is critical when comparing water activity results between samples or production batches.
For routine measurements:
The PCE-WAM 20 is the higher-performance option in Cambridge's portable PCE water activity range. It provides much finer resolution, improved accuracy, multi-point calibration and substantially greater data storage than the entry-level WAM 10 and WAT 10.
| Feature | PCE-WAM 10 | PCE-WAT 10 | PCE-WAM 20 |
| Positioning | Entry-level routine QA/QC | Step-up portable QA/QC | High-precision QA/QC & R&D |
| aw Resolution | 0.01 aw | 0.01 aw | 0.0001 aw |
| Published Accuracy | ±0.03 aw | ±0.02 aw | ±0.015 aw at 10–30°C |
| Typical Test Time | Approx. 5 min | Approx. 5 min | Approx. 3–5 min |
| Calibration | Basic | Basic | 1–4 point |
| Stored Results | No standard onboard memory listed | 99 | 5,030 |
| Measurement Modes | Routine | Routine | Normal / Fast / Continuous |
| Display | LCD | LCD | 2.8" Colour TFT |
| PC Data Transfer | Optional / configuration dependent | Limited | USB-C + PC software |
Choose the PCE-WAM 10 for economical routine water activity screening where ±0.03 aw accuracy is sufficient.
Choose the PCE-WAT 10 when you want a portable meter with ±0.02 aw accuracy and onboard storage for up to 99 measurements.
Choose the PCE-WAM 20 when you need 0.0001 aw resolution, ±0.015 aw published accuracy, multi-point calibration, more than 5,000 stored measurements and PC data transfer.
| Model | PCE-WAM 20 |
| GTIN / EAN | 4250348737052 |
| Water Activity Range | 0.0000 to 1.0000 aw |
| Water Activity Resolution | 0.0001 aw |
| Water Activity Accuracy | ±0.015 aw from 10 to 30°C |
| Typical Measurement Time | Approximately 3–5 minutes |
| Measurement Modes | Normal, Fast, Continuous |
| Temperature Range | -10 to 50°C / 14 to 122°F |
| Temperature Resolution | 0.01°C / 0.018°F |
| Temperature Accuracy | ±0.1°C / ±0.18°F |
| Number of Measurement Channels | 1 |
| Sensor Type | Capacitive |
| Sensor Cable Length | 1.8 m / 5.9 ft |
| Calibration | 1 to 4 points |
| Display | 2.8" TFT colour display |
| Internal Memory | 5,030 data records |
| Interface | USB-C |
| PC Software | Available from PCE download area |
| Menu Languages | English, French, Spanish, Chinese |
| Protection Class | IP20 |
| Power Supply | 5 V USB or 4 × 1.5 V AA batteries |
| Operating Conditions | -10 to 40°C / 14 to 104°F, 0–90% RH |
| Storage Conditions | -10 to 40°C / 14 to 104°F, 0–90% RH |
| Dimensions | 217 × 100 × 35 mm / 8.5 × 3.9 × 1.4 in. |
| Weight | 280 g / 0.6 lb |
The instrument has an IP20 protection rating. Keep the meter, sensor and electrical connections protected from water, washdown, condensation and direct contact with sample liquids.
The standard PCE-WAM 20 should not be assumed to include an ISO calibration certificate. PCE offers a separate PCE-WAM 20-ICA configuration that includes an ISO calibration certificate. Confirm calibration-documentation requirements before ordering.
PCE specifies an accuracy of ±0.015 aw when the sample temperature is between 10 and 30°C.
The PCE-WAM 20 displays water activity to 0.0001 aw.
The PCE-WAM 20 measures from 0.0000 to 1.0000 aw.
PCE specifies approximately 3 to 5 minutes for water activity measurements. Actual stabilization time can depend on the sample, temperature and selected measurement mode.
The instrument provides Normal, Fast and Continuous measurement modes.
The meter supports calibration using one, two, three or four points.
The internal memory stores up to 5,030 measurement records.
Yes. The meter has a USB-C interface and PCE provides PC software for transferring and working with measurement data.
Yes. The instrument measures temperature from -10 to 50°C with 0.01°C resolution and ±0.1°C accuracy.
No. The meter has an IP20 protection rating and should be kept protected from water, washdown and condensation.
Yes. Its ±0.015 aw published accuracy, 0.0001 aw resolution, 3–5 minute measurement time, multi-point calibration and data storage make it well suited to food production QA/QC and product-development applications.
Yes. Water activity can provide important information during shelf-life studies, but it should be evaluated together with microbiological, chemical, physical, formulation, packaging and storage data appropriate to the product.
No. Moisture content measures total water in a sample, while water activity describes how available that water is for microbial growth and other reactions.
The PCE-WAM 20 provides 0.0001 aw resolution, ±0.015 aw published accuracy, 1- to 4-point calibration, 5,030 stored records and USB-C data transfer. The PCE-WAT 10 is a simpler portable meter with 0.01 aw resolution, ±0.02 aw accuracy and 99 stored results.
The WAM 10 is intended for economical routine water activity measurements with 0.01 aw resolution and ±0.03 aw accuracy. The WAM 20 provides much finer 0.0001 aw resolution, improved ±0.015 aw published accuracy, multi-point calibration, advanced measurement modes and extensive data storage.
The standard PCE-WAM 20 delivery scope does not list an ISO calibration certificate. PCE offers a separate PCE-WAM 20-ICA configuration with an ISO calibration certificate.
The standard PCE-WAM 20 package includes 10 sample trays and a sample holder.
Cambridge Environmental Products supplies the PCE-WAM 20 Water Activity Meter in Canada along with water activity standards, sample consumables and other aw measurement systems for food and beverage, pharmaceutical, cosmetics, agriculture and laboratory applications.
Cambridge Environmental Products supplies water activity meters, calibration standards, sample consumables and related QA/QC equipment across Canada.
If you are unsure whether the PCE-WAM 20 is the right level of instrument for your application, send us your sample type, expected water activity range, number of measurements per day, required accuracy, calibration requirements and data-management needs.
The PCE-WAM 20 is a strong choice for production QA/QC and R&D laboratories that need substantially more precision and data capability than an entry-level portable aw meter without moving to a more complex laboratory water activity platform.
Send Cambridge your application and we can help compare accuracy, resolution, calibration, sample throughput and data-management requirements across the available water activity systems.
