PR291/PR293 Series Nanovolt & Microhm Thermometer

• 10nV/10μΩ Resolution

• 30PPM Measurement Accuracy

• Automatic Reset of Parasitic Potential

• Multiple Full-function Measurement Channels

1. Overview

The PR291/PR293 series nanovolt & microhm thermometers are high-precision measuring instruments specifically designed for the field of temperature metrology. They feature measurement resolutions of 10nV/10μΩ and optimal measurement accuracy reaching 30ppm. Combining excellent high precision and high resolution with a portable design, they provide a more flexible and efficient measurement solution for temperature metrology.

Compared to general-purpose high-precision digital multimeters (DMMs), the PR291/PR293 series thermometers are better suited for temperature metrology in terms of range, functionality, accuracy, and ease of use. They incorporate 2 or 5 fully-functional rear-panel measurement channels. The range options are expanded to include 20mV and 400Ω specifically to match standard thermocouples and Pt100 sensors. Additionally, they offer three operational modes – patrol inspection, single-channel tracking, and temperature difference measurement – for ease of operation.

1.1 Appearance

PR293AP Rear-Panel Measurement Channels

PR293BP Rear-Panel Measurement Channels

 PR291BP Rear-Panel Measurement Channels

1.2 Features

• Measurement Resolution 10nV/10μΩ

The breakthrough design of the ultra-low-noise amplifier and the miniature low-ripple power supply module significantly reduces reading noise in the thermometer's signal path. Combined with the application of novel digital filtering technology, 8-digit resolution is achievable in certain measurement ranges.

• Excellent Annual Stability

The instrument incorporates built-in reference-grade standard resistors and an oven-controlled reference, featuring an extremely low temperature coefficient (TC) and excellent long-term stability, with accuracy reaching 30ppm. Even when operating in field environments between -5°C to 35°C, it maintains excellent measurement accuracy.

• Parasitic EMF Auto-Nulling

All measurement channels incorporate independent hardware zero self-calibration. This enables real-time elimination of range errors caused by parasitic EMFs (electromotive forces) or drift within the measurement loop, eliminating the need for additional polarity reversal switches.

• Integrated Multi-Channel Low Noise Scanner

In addition to the front channel, depending on the model, the rear panel integrates 2 or 5 groups of independent full-function test terminals. Each group of channels can independently set the test signal type, and has extremely high consistency between channels, without any external switch, it can carry out multi-channel data acquisition.

• Multifunctional Tellurium Copper Terminals

The rear channels all use push-type multi-functional tellurium copper terminals, which are gold-plated with tellurium copper, which has excellent electrical connection performance and can provide a variety of wire connection methods.

• Three Working Modes

It has three working modes: patrol inspection, single-channel tracking, and temperature difference measurement. When the single-channel tracking mode working, the thermometer is used in a similar manner to a conventional digital multimeter. The temperature difference measurement mode can analyze the temperature field uniformity of various constant temperature equipment.

• Rich Temperature Metrology Functions

Compared with the traditional digital multimeter, the 20mV range for measuring S-type thermocouples and the 400Ω range for PT100 platinum resistance measurement are added. At the same time, conversion programs for various temperature sensors are built-in, the certificate value or the corrected value can be quoted to carry out temperature traceability of the test results. Simultaneously, all measurement channels feature dedicated thermocouple (TC) jacks with accuracy better than 0.2℃.

• Data Analysis Function

In addition to displaying various test data, curves and data storage functions, the thermometer can also perform maximum/minimum/average calculations for real-time data, and perform various calculations of temperature fluctuations.

• Portable Design

Compared with the thermometers of the same level, it has a smaller volume and weight, which is convenient for high-level temperature testing in various field environments. The design of the built-in high-capacity lithium battery also makes it easier to use.

1.3 Partial Work Interface

2. Technical Parameters

2.1 Model Selection

2.2 Electrical Technical Parameters

2.3 Technical Parameter

• Temperature Measurement with Platinum Resistor(RTD)

• Temperature Measurement for Thermocouples

• Built-in Thermocouple Reference Junction Technical Parameters

3. Packaging Information

Standard Accessories

Optional Accessories