Frequently Asked Questions

1. How do I turn the thermometer on and off?

There are no physical buttons on this device. The thermometer automatically switches ON the moment you pull it out of its plastic storage case and switches OFF as soon as you slide it completely back into the case.

2. What is the difference between "Predictive" and "Direct" measurement modes?

The C407 features a dual-measurement mode system:

• Predictive Mode (Fast): Takes roughly 30 seconds. A built-in microprocessor analyzes the speed of temperature change at the sensor tip and calculates your final body temperature based on statistical algorithms. It will emit an audible beep when this calculation is ready.

• Direct Mode (Actual): If you keep the thermometer in place after the initial beep, it automatically switches to direct reading mode. It will continue to record the actual heat of the tissue over roughly 5 minutes for a final, direct measurement.

3. Can I use the light blue C407 model for underarm (axillary) readings?

No, it is not recommended. Terumo thermometers are strictly color-coded to prevent cross-contamination and ensure precision calibration.

• Light Blue (C407): Specifically calibrated for Oral and Rectal temperature rise curves.

• Green (C207): Specifically calibrated for Axillary (Underarm) temperature rise curves.

Using an oral/rectal model under the arm can compromise the accuracy of the 30-second predictive reading, as the skin tissue warms up differently than mucous membranes.

4. How do I change the internal batteries?

The internal lithium batteries are completely sealed inside the waterproof casing to maintain its clinical IPX7 rating (submersible protection) and prevent cross-contamination in medical environments. The long-life battery is engineered to last for approximately 10,000 measurements (roughly 3 years in a busy clinical setting). Once the battery is completely exhausted, the entire unit must be replaced.

5. What is the best way to clean and disinfect the unit?

Because the thermometer is completely sealed and waterproof, the entire unit—including the digital display, sensor tip, and battery compartment—can be safely washed with water or wiped down with alcohol and common clinical antiseptic solutions. The hard storage case can also be completely wiped down and disinfected between uses.