1. Introduction
The AMTAST WA-60A Portable Water Activity Meter is designed for precise measurement of water activity (aw) in various substances, including food products like beef jerky, freeze-dried food, fruits, and vegetables. This device helps assess product preservation and stability by quantifying the free water content. Its portable design and integrated sensor make it a convenient tool for on-site analysis.
2. Product Overview
Figure 2.1: The AMTAST WA-60A Water Activity Meter in use, displaying a water activity reading. This device measures free water activity to assess the preservation and stability of food, medicine, and other products.
Figure 2.2: The AMTAST WA-60A Water Activity Meter with its sample plate. The kit typically includes the meter, sample plate, portable bag, and manual for accurate measurement of free water content.
Key Features:
- Portable Design: Weighing approximately 100 grams, this meter is lightweight and suitable for on-the-go testing.
- Accurate Measurements: Offers a measurement range of 0-1.0aw with a resolution of ±0.01aw and an accuracy of 0.02aw.
- Integrated Sensor: Features a non-conductive humidity sensor and integrated readings in a single unit, simplifying water activity analysis.
- Quick Testing: Provides rapid results, typically completing measurements within 5 minutes.
- Clear Display: Equipped with a 6-digit backlit LCD screen that simultaneously displays water activity (aw) and temperature.
- User-Friendly Functions: Includes automatic and manual shut-off options, along with a low battery indicator.
Figure 2.3: Detailed view of the meter's backlit LCD screen, showing both the water activity (aw) and temperature values for clear readings.
Figure 2.4: Image showing the battery compartment for 2x1.5V AAA batteries and the non-conductive humidity sensor. The device also features automatic shutdown, manual shutdown, and alarm indication.
3. Specifications
Figure 3.1: The AMTAST WA-60A Water Activity Meter shown alongside its key specifications.
| Parameter | Value |
|---|---|
| Model Number | WA-60A |
| Measurement Range | 0.00 ~ 1.00 aw |
| Resolution | ±0.01 aw |
| Accuracy | ±0.02 aw |
| Temperature Operation Conditions | 0-50°C |
| Humidity Operation Conditions | <95% RH |
| Item Weight | 100 grams (3.53 ounces) |
| Power Supply | 2 x 1.5V AAA Size (UM-4) Battery (not included) |
| Material | ABS |
| Dimensions | Approximately 13.5 cm (5.3 inches) height, 7 cm (2.8 inches) width |
4. Setup
Before first use, ensure the device is properly set up.
- Battery Installation: Open the battery compartment on the back of the meter. Insert two 1.5V AAA batteries, ensuring correct polarity. Close the compartment securely.
- Sample Holder: The meter comes with a sample holder featuring a strong magnetic connection. Ensure the sample holder is clean and dry before use.
- Calibration (Highly Recommended): For accurate and reliable results, especially for food safety applications, it is highly recommended to calibrate the meter using certified water activity standards. This should be done in the range relevant to your testing.
Video 4.1: This video demonstrates the setup and basic operation of the AMTAST WA-60A Water Activity Meter, including how to prepare samples for measurement.
5. Operation
Follow these steps for accurate water activity measurement:
- Prepare Sample: Place your sample into a clean, dry sample cup. Ensure the sample fills the cup adequately without overflowing.
- Place Sample: Position the sample cup onto the base of the meter. The magnetic sample holder will secure it in place.
- Equilibration: Crucial Step: After placing the sample and closing the meter, allow sufficient time for the sample to equilibrate with the sensor. This process can take several hours, or even overnight, depending on the sample type and environmental conditions. Do not turn on the meter immediately.
- Power On: Once the sample has equilibrated, turn on the meter while it is still closed on the sample.
- Read Measurement: The LCD screen will display the water activity (aw) and temperature. Allow the reading to stabilize before recording the final value.
- Power Off: The device features automatic and manual shut-off options. To manually turn off, press and hold the power button.
Video 5.1: This video provides a general overview of the AMTAST Smart Water Activity Meter, demonstrating its use in a laboratory setting.
Video 5.2: This video demonstrates the process of using the Water Activity Meter for monitoring food water activity (AW).
Figure 5.1: The meter is designed for quick and efficient testing, providing accurate readings for water activity measurements.
Figure 5.2: The AMTAST WA-60A is widely used for testing water activity in various food products, including dried fruits, beef jerky, cookies, and sausages.
6. Maintenance
- Cleaning: Keep the sample holder and sensor area clean and free from debris. Use a soft, dry cloth to wipe the device. Do not use abrasive cleaners or immerse the device in water.
- Storage: Store the meter in its protective case in a cool, dry place when not in use. Remove batteries if storing for extended periods to prevent leakage.
- Calibration: Regular calibration with known standards is essential to maintain accuracy. Refer to Section 4 for calibration recommendations.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Inaccurate or erratic readings | Insufficient equilibration time; lack of calibration; dirty sensor. | Ensure sample equilibrates for several hours before measurement. Calibrate the device regularly with appropriate standards. Clean the sensor and sample holder. |
| Device does not power on | Dead or incorrectly installed batteries. | Check battery polarity. Replace batteries with fresh 1.5V AAA batteries. |
| Display is dim or unreadable | Low battery. | Replace batteries. |
8. Safety Information
- Do not attempt to disassemble or repair the device yourself. Contact qualified personnel for service.
- Keep the device away from extreme temperatures, humidity, and direct sunlight.
- Handle the device with care to avoid physical damage.
- Dispose of batteries according to local regulations.
9. Warranty and Support
For warranty information, technical support, or service inquiries, please contact AMTAST customer service. Refer to the product packaging or the official AMTAST website for contact details.
AMTAST Official Store: Visit the AMTAST Store on Amazon
