RTD series: FAQ and Troubleshooting guide

Frequently Asked Questions

What are the main differences between the various RTD models?

RTD223 have the RTD Pt100 probe connected via a terminal block, whereas RTD200 and RTD300 connect the probe to the adapter using a connector.

RTD300 has a resolution of ±0.0005°C, while the resolution of the other three is ±0.02°C. We also offer a pre-wired probe optimized for use with RTD300 to achieve this resolution. For detailed specifications, please consult our RTD series comparison guide.

Can the probes be submerged in water?

Yes, RTD probes can be submerged in water, but USB adapters cannot.

Why did you choose to offer only one type of RTD probe?

There are numerous RTD Pt100 probes suitable for all possible temperature measurement scenarios. While we are not distributors of temperature probes, we wanted to provide a complete solution on our platform. Therefore, we selectively chose a probe that could meet the needs of the majority of our users.

Can I use any probe of my choice with your adapters?

Certainly! These are universal adapters for 2 or 3-wire RTD Pt100 1/3 DIN (Class AA) probes. 4-wire probes can also be used, but the increased accuracy of this type of probe compared to a 3-wire probe will be lost during connection.

Can a RTD probe be used at temperatures beyond the announced operating temperature range of the housing (0°C to 50°C)?

To measure temperature, only the probe should be placed in an environment hotter than 50°C. Additionally, the advertised accuracy for the adapters is optimal at 25°C.

How do I connect my RTD probe to the adapter?

For the RTD200 and RTD300, a three-pin connector is provided with the adapter. You simply need to open it and connect the wires from your RTD probe. Then, insert the connector into the USB adapter, and you’re good to go! The connector is also difficult to remove from the adapter, making the construction very robust.

Can I have a STEP/CAD file of the purchased RTD for its dimensions?

Yes you can. These are available on the product page, under the “Datasheets” section. Also note that all the housing dimensions are indicated in the product datasheet.

What calibration is performed on the instruments during production?

All RTD adapters are similarly calibrated in production. Using a precision probe at ambient temperature, the programming software calibrates the adapter to meet the specifications, such as ±0.001°C for the RTD300.

Is the individual calibration of the measuring instruments done at the Dracal factory

At the Dracal production factory, a pass/fail type of testing is conducted during the production of the measuring instrument. Additionally, the component manufacturer carries out individual calibration at their factory before being shipped to us. These calibrations are not ISO17025 certified, but if your industry does not require this standard, you can confidently use Dracal’s USB adapters upon receiving them.Is an external probe necessary for calibrating the adapter?

No, having a probe to calibrate the adapter is unnecessary. Without a probe, the laboratory will use an instrument that simulates the presence of a theoretical RTD probe. However, if possible, it is preferable to calibrate the device with the final probe to compensate for the probe’s error in calibration and achieve better accuracy.

Is an external probe necessary for calibrating the adapter?

No, having a probe to calibrate the adapter is not required. To verify the RTD meter on its own, the laboratory will use an instrument that simulates the presence of a theoretical RTD probe. For instance, our partner laboratory Transcat simulates a known resistance value based on the PT385 curve. This is done using a resistance decade box in combination with a high-accuracy long-range DMM. The decade box is first connected to an Agilent 3458A in a 4-wire configuration and adjusted until the DMM reads the exact target resistance (e.g., 100.000 Ω, which corresponds to 0.00 °C). The DMM ensures precise resistance settings. Once the exact value is achieved, the DMM is disconnected, and the RTD meter is connected to the decade box to check its reading. This allows them to simulate any PT385 resistance point for verification.

But in most cases, our clients choose to send the complete system—the RTD meter along with the probe they intend to use—because the probe contributes the largest uncertainty. For example, the RTD300 meter has a specification of ±0.035 °C, while a Class A RTD probe has an uncertainty of ±0.15 °C at 0 °C. Calibrating them together ensures the combined performance meets requirements.

Your question or issue is not covered here?

For additional support, please do not hesitate contact our technical team. We typically answer in less than 1 business day.