Frequently Asked Questions: AS ONE WT-200 Waterproof Digital Thermometer with HACCP Alert Function:

1. What is the AS ONE WT-200 and what applications is it suited for?

The WT-200 is a handheld waterproof digital thermometer (model 2-3799-02) featuring an HACCP alert function. It’s designed for precise temperature monitoring in food processing, cold storage, laboratories, healthcare settings, and agricultural environments where liquid or spray resistance is required.

2. What is the measurement range and accuracy of the WT-200?

The WT-200 measures temperatures from –40 °C to +250 °C. It offers an accuracy of ±0.1 °C within the –9.9 °C to +199.9 °C range and ±1 °C outside that span.

3. What resolution and sampling cycle does the WT-200 provide?

It delivers a resolution of 0.1 °C between –19.9 °C and +199.9 °C, and 1 °C for readings beyond that. The sampling frequency is two measurements per second, ensuring fast response.

4. What type of sensor and probe materials are used?

The WT-200 uses a thermistor sensor paired with a stainless steel (SUS304) probe. The probe is connected by an approximately 1 m cable, allowing flexible placement while keeping the main unit dry.

5. What waterproof protection does the WT-200 offer?

The instrument body meets IPX6 standards for resistance to powerful water jets, and the sensor probe itself is rated IPX7, making it safe for brief immersion in water.

6. Which key functions and features does the WT-200 include?

Measurement value hold

Maximum and minimum temperature display

Auto power-off to conserve battery

Built-in clock and timer

Audible buzzer and LED backlight

HACCP alert with configurable high/low thresholds

Standard probe accessory included

7. How do I power on and perform a basic temperature measurement?

Open the battery cover and insert two AA batteries as shown.

Slide the ON/OFF switch to power on; the display will initialize.

Place the probe tip in the sample, waiting a few seconds for the reading to stabilize.

Press the “Hold” button to freeze the current reading on screen.

8. How do I configure and use the HACCP alert function?

While measuring, press and hold the “HACCP” button until the display blinks.

Use the ▲/▼ keys to set the lower alarm limit, then confirm.

Repeat to set the upper alarm limit, then confirm again.

When temperature crosses either threshold, the unit sounds a buzzer and flashes its LED.

Press “HACCP” to silence the alarm once conditions return within range.

9. How do I replace the batteries and manage power saving?

Replace the two AA batteries when the display dims or the LED weakens.

The WT-200 automatically shuts off after approximately 10 minutes of inactivity to extend battery life.

10. How should I clean and maintain the WT-200?

Wipe the body and probe cable with a damp cloth; avoid submerging the main unit.

Rinse the stainless steel probe under clean water and dry thoroughly before use.

Do not use strong solvents (e.g., acetone, high-proof alcohol) on any part of the thermometer.

Periodically inspect the probe’s O-ring seal to ensure waterproof integrity.

11. What are common error messages and troubleshooting steps?

“Err” or unstable readings: clean the probe and ensure it’s fully inserted.

No display or faint backlight: replace the AA batteries and verify correct polarity.

HACCP alarm won’t reset: press and hold “HACCP” until the buzzer stops.

12. What accessories are available, and what warranty applies?

Optional replacement probe (model 2-3799-03) with similar length and temperature rating.

Protective carrying pouch and probe clip as accessories.

The WT-200 and its probe come with a 12-month manufacturer’s warranty against defects.

13. Where can I purchase the WT-200 and obtain technical support?

The WT-200 is available through AS ONE’s authorized distributors and laboratory equipment suppliers. For pricing, calibration services, or application advice, contact your local AS ONE representative - QTE Technologies.