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Frequently Asked Questions for SmartReader 1 and 8, and SmartReader Plus 1 and 8

Are your probes waterproof?

No, our probes are not waterproof. However, the tips are stainless steel and water-resistant.

Can I connect my own thermistor probe to these loggers?

Yes, you can. You will need to create a custom equation. To create a custom equation, you need to know the resistance of your probe at the three (low, mid and high) temperatures. Please refer to the Equation section (page 106) of TrendReader 2 Reference Guide for the details.

If I use my own probe, which equation number should I use?

You should create a thermistor equation for your probe. The procedure for creating a thermistor equation can be found in the Equation section of the TrendReader 2 Reference Guide.

What is the accuracy of these loggers?

The accuracy of SR1 and SR8 at 25°C is ±0.6°C (1.1°F at 77°F).

The accuracy of SRP1 and SRP8 at 25°C is ±0.23°C (0.42°F at 77°F).

Note: The accuracy of the system is equal to the accuracy of the Thermistor Probe plus the resolution of the data logger. Thermistors are non-linear. This means that the accuracy of the Thermistor Probe varies over the entire temperature range of the logger. Therefore, the total accuracy of the system depends on the temperature range.

For example, let’s assume you use the ET-016 probe, a General Purpose temperature probe that is suitable for the range –35 to 95°C (-30 to 200°F). The accuracy of this probe is:

±0.2°C between 0 and 70°C (±0.36°F between 32 and 158°F)

±1.0°C above 70°C and below 0°C (±1.8°F above 158°F and below 32°F)

The total accuracy of the system depends on the temperature and whether you are using a SmartReader or SmartReader Plus logger.

The accuracy curves for the SR1, SRP1, SR8 and SRP8 loggers, with the ET-016 external thermistor probes with lengths less than 100 feet, are shown on page 48 of the latest catalog. These curves also apply to the internal temperature channels on these loggers. For the “Resistance versus Temperature Tables” and the Thermistor Probe resolution curves, please refer to Appendix C of the Reference Guide.

Can I connect a Thermocouple Probe to this logger?

No, you can connect only Thermistor Probes to SR1,SRP1,SR8 and SRP8 loggers.

What is the maximum recommended cable length of the ET temperature probes?

These temperature probes use a resistive thermistor. The thermistor resistance varies with temperature. Since the conductor has an inherent resistance, there is a limit to the length of the conductor that can be added to a Thermistor Probe (without affecting readings). The maximum recommended length is 100 feet of two-wire 22-gauge standard conductor.


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