AMTAST AMT158 Portable Water Activity Meter User Manual

1. Introduction

This manual provides detailed instructions for the AMTAST AMT158 Portable Water Activity Meter. It covers the product's features, technical specifications, proper setup, operational procedures, maintenance guidelines, and troubleshooting steps. Please read this manual thoroughly before using the device to ensure accurate measurements and safe operation.

2. Product Overview

2.1 Key Features

Lightweight & Portable: Weighing approximately 275 grams, the meter is designed for easy transport and on-the-go testing.
Accurate & Reliable Measurements: Offers a measurement range of 0-1.0aw with a resolution of ±0.01aw and an accuracy of ±0.02aw for precise water activity analysis.
Integrated Sensor: Features a non-conductive humidity sensor and integrated readings within a single unit, simplifying the measurement process.
Quick Testing Process: Provides rapid results, completing water activity measurements within approximately 5 minutes.
Convenient Display & Functions: Equipped with a 6-digit backlit LCD screen displaying both water activity (aw) and temperature simultaneously. Includes automatic and manual shut-off options, and a low battery indicator.

2.2 Components

The AMTAST AMT158 Water Activity Meter package typically includes the main unit (host), a sample plate, a portable carrying bag, and this instruction manual.

**Figure 1:** AMTAST AMT158 Water Activity Meter in a laboratory setting, illustrating its function to measure free water activity for food and medicine preservation. The image also shows a sample plate, which is a key component.

3. Specifications

Parameter	Value
Measurement Range	0 ~ 1.0aw
Resolution	±0.01aw
Accuracy	±0.02aw
Sampling Time	5 Minutes
Operating Temperature	0 ~ 50℃ (32 ~ 122℉)
Operating Humidity	<95%RH (non-condensing)
Power Supply	2 x 1.5V AAA Size (UM-4) Battery
Dimensions	145 x 77 x 30mm (5.7 x 3.0 x 1.2 inches)
Weight (without batteries)	275g (0.61 lbs)

Diagram showing the dimensions and specifications of the AMTAST AMT158 Water Activity Meter — **Figure 2:** Diagram illustrating the physical dimensions (5.7 inches height, 3.0 inches width) and key technical specifications of the AMTAST AMT158 Water Activity Meter.

4. Setup

4.1 Battery Installation

Locate the battery compartment cover on the back of the device.
Slide or unclip the cover to open it.
Insert two (2) 1.5V AAA (UM-4) batteries, ensuring correct polarity (+/-) as indicated inside the compartment.
Replace the battery compartment cover securely.

Note: Batteries are not included in the package due to aviation security regulations.

Battery compartment and sensor of the AMTAST AMT158 Water Activity Meter — **Figure 3:** Detailed view of the AMTAST AMT158 Water Activity Meter's battery compartment, showing where to insert the 2x1.5V AAA batteries, and the non-conductive humidity sensor.

4.2 Initial Inspection

Before first use, inspect the device for any visible damage. Ensure the sample plate is clean and free from debris. The sensor should also be clean and unobstructed.

5. Operation

5.1 Powering On/Off

To power on the device, press the power button (usually marked with a ⑂ symbol). The backlit LCD screen will illuminate.
The device features an automatic shut-off function to conserve battery power. To manually shut off the device, press and hold the power button until the display turns off.

5.2 Taking a Measurement

Ensure the sample plate is clean and dry.
Place a small, representative sample of the material to be tested onto the sample plate. Ensure the sample covers the sensor area adequately without overflowing.
Close the meter's lid or place the main unit onto the sample plate, ensuring a tight seal to create a closed environment for accurate measurement.
The measurement process will begin automatically or may require a button press (refer to specific on-screen prompts if any). The device will typically take approximately 5 minutes to stabilize and display the final water activity (aw) and temperature readings.
Once the reading is stable, record the displayed values.
After measurement, remove the sample and clean the sample plate and sensor area immediately.

**Figure 4:** Close-up of the AMTAST AMT158 Water Activity Meter's backlit LCD screen, clearly displaying both the water activity (aw) value and the temperature.

AMTAST AMT158 Water Activity Meter emphasizing quick 5-minute measurement — **Figure 5:** The AMTAST AMT158 Water Activity Meter highlighting its quick and efficient measurement capability, completing tests within 5 minutes.

5.3 Applications

The AMTAST AMT158 Water Activity Meter is suitable for measuring water activity in a wide range of products, including but not limited to:

Dried fruits and vegetables
Beef jerky and other dried meats
Baked goods like cookies
Sausages and processed meats
Grains, nuts, and spices

Collage of food items illustrating the wide application of the AMTAST AMT158 Water Activity Meter — **Figure 6:** A visual representation of various food products such as dried fruit, beef jerky, cookies, and sausage, demonstrating the broad utility of the AMTAST AMT158 Water Activity Meter in different food applications.

6. Maintenance

6.1 Cleaning

After each use, carefully clean the sample plate and the area around the sensor with a soft, dry cloth.
Do not use abrasive cleaners or solvents, as these can damage the sensor or the device's casing.
Ensure no liquid enters the device's internal components.

6.2 Storage

Store the meter in a clean, dry environment, away from direct sunlight and extreme temperatures. When storing for extended periods, remove the batteries to prevent leakage.

6.3 Battery Replacement

When the low battery indicator appears on the display, replace both AAA batteries promptly to ensure continued accurate operation. Refer to Section 4.1 for battery installation instructions.

7. Troubleshooting

Problem	Possible Cause	Solution
Device does not power on	Dead or incorrectly installed batteries	Check battery polarity; replace with fresh batteries.
Inaccurate or inconsistent readings	Sensor contamination Improper sample placement Device not calibrated (if applicable) Environmental interference (temperature/humidity outside operating range)	Clean the sensor and sample plate thoroughly. Ensure the sample covers the sensor and the lid is sealed. If calibration is required, refer to specific calibration instructions (not covered in this general manual). Ensure operating conditions are within specified ranges (0-50℃, <95%RH).
Display shows 'Low Battery'	Batteries are low	Replace both 1.5V AAA batteries.
Device beeps continuously	Possible internal error or battery issue	Remove and reinsert batteries. If the issue persists, contact customer support.

8. Warranty and Support

For warranty information, technical support, or service inquiries, please contact the manufacturer or your authorized dealer. Keep your purchase receipt as proof of purchase.

You can visit the official AMTAST store for more information: AMTAST Store on Amazon

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AMTAST AMT158