PT-104 High-accuracy data logger

The Pico PT-104 High-Accuracy Data Logger is designed for engineers, calibration laboratories, research facilities and industrial users who require precise and stable temperature measurements using platinum resistance thermometers.

The PT-104 provides four measurement channels and supports both PT100 and PT1000 PRT sensors. It can work with 2-wire, 3-wire and 4-wire sensor configurations, with 4-wire measurement recommended for the highest accuracy because it minimizes errors caused by lead resistance.

High-Accuracy Temperature Measurement

The PT-104 is designed specifically for precision PRT temperature measurement.

Its published temperature performance includes:

• Measurement range: −200 °C to +800 °C
• Resolution: 0.001 °C
• Accuracy at 23 ±2 °C: 0.015 °C + 0.01% of reading
• Temperature coefficient: 5 ppm/°C
• RMS noise with filtering: 0.01 °C
• ADC resolution: 24 bits

This combination of high resolution and low measurement error makes the PT-104 suitable for applications where small temperature changes need to be measured and recorded accurately.

PT100 and PT1000 Sensor Support

The PT-104 supports the two widely used platinum resistance thermometer standards:

• PT100
• PT1000

Sensor connections can be configured as:

• 2-wire
• 3-wire
• 4-wire

For precision measurements, Pico recommends using 4-wire PT100 sensors because this arrangement compensates more effectively for resistance in the sensor leads.

Typical compatible probe applications include:

• Air temperature
• Surface temperature
• Liquid temperature
• Environmental chambers
• Industrial processes
• Calibration baths
• Laboratory experiments
• Equipment thermal monitoring

Stable Reference Resistor Design

Instead of relying only on conventional voltage references, the PT-104 uses high-precision reference resistors with low temperature coefficient and drift.

The exact value of each reference resistor is stored internally, helping maintain stable measurement performance over time.

This design is particularly useful in high-accuracy temperature applications where changes in the measurement electronics could otherwise influence the recorded result.

24-Bit Analog-to-Digital Conversion

The PT-104 uses a high-performance 24-bit ADC to achieve its 0.001 °C temperature resolution.

High converter resolution allows the instrument to resolve very small changes in the resistance of a PT100 or PT1000 sensor and convert those changes into detailed temperature measurements.

Resistance Measurement

In addition to temperature, the PT-104 can directly measure resistance.

Two resistance ranges are available:

• 0 to 375 Ω
• 0 to 10 kΩ

Pico recommends the 0 to 375 Ω range for the highest accuracy, as the unit is calibrated specifically for this range.

Resistance performance includes:

• Accuracy: 50 ppm at 100 Ω
• Resolution: 1 µΩ
• Temperature coefficient: 5 ppm/°C
• RMS noise with filter: 10 ppm

For resistance measurement, the PT-104 uses a 4-wire circuit to minimize errors caused by test-lead resistance.

Voltage Measurement Capability

The PT-104 hardware and driver also support voltage measurement.

In voltage mode, each input can operate as a differential voltage input referenced to ground. The maximum input voltage measurement range is 2.5 V.

When using the PicoSDK, each connector can alternatively be configured as two single-ended voltage inputs, increasing the potential voltage-input channel count from four to eight.

Single-ended voltage mode is supported through the driver and PicoSDK, but is not supported by PicoLog software.

For third-party voltage-output sensors, the optional PP660 screw terminal adaptor can simplify connection.

Four Measurement Channels

The PT-104 provides:

• 4 physical input channels
• 4-pin mini-DIN input connectors
• Independent PT100/PT1000 or resistance measurement on each channel

With four PRT probes connected, engineers can monitor multiple measurement points at the same time.

Typical examples include:

• Four points within an environmental chamber
• Inlet and outlet temperatures
• Multiple locations on an electronic assembly
• Reference and DUT temperature comparison
• Thermal uniformity measurements

Expandable Up to 80 Temperature Channels

PicoLog software supports up to 20 PT-104 units on a single computer.

This allows a maximum configuration of:

• 4 channels per PT-104
• Up to 20 units
• Up to 80 PRT measurement channels

Multiple PT-104 units can therefore be used for larger temperature monitoring systems without requiring a completely different acquisition platform.

USB Connectivity

For local measurement setups, the PT-104 can connect directly to a computer through USB.

USB operation provides:

• Data communication
• Device power
• Simple laboratory setup
• Portable measurement operation

The PT-104 is compatible with USB 1.1 and later USB interfaces according to Pico's current specifications.

Ethernet and Remote Monitoring

The PT-104 also includes an Ethernet interface, allowing the logger to be positioned away from the measurement computer.

This is useful for:

• Remote laboratory monitoring
• Long-duration tests
• Industrial test environments
• Environmental chambers
• Distributed measurement systems
• Equipment monitoring

In current PicoLog operation, Ethernet connectivity is supported under Windows.

Power over Ethernet

The PT-104 can receive power from:

• USB
• Compatible Power over Ethernet infrastructure

Using PoE can reduce cabling in remote measurement installations because communication and power can be provided through the Ethernet connection.

Compatible Power Sourcing Equipment, such as an appropriate PoE network switch, router or injector, is required.

PicoLog Cloud Software

The PT-104 works with PicoLog Cloud, Pico Technology's data acquisition and logging software.

PicoLog provides functions including:

• Real-time temperature monitoring
• Multi-channel graphing
• Channel configuration
• Alarm settings
• Notes and annotations
• Multiple Y axes
• Long-duration data recording
• Pan and zoom
• CSV export
• PDF export
• PicoLog database storage
• Cloud capture sharing

This makes the PT-104 suitable for both short laboratory tests and longer unattended monitoring applications.

PicoLog Cloud Remote Data Access

PicoLog Cloud can be used to upload compatible measurement captures for remote browser-based access.

This can support:

• Remote temperature monitoring
• Distributed engineering teams
• Long-running experiments
• Shared laboratory data
• Remote review of measurement results

PicoSDK for Custom Applications

Pico also provides PicoSDK for developers who need to control the PT-104 from custom software.

Pico provides example code and programming support for building:

• Automated test applications
• Calibration systems
• Custom laboratory software
• Production monitoring tools
• Research instrumentation
• Database-connected measurement systems

Typical Applications

The Pico PT-104 is suitable for:

• Precision temperature measurement
• PT100 data logging
• PT1000 data logging
• Calibration laboratories
• Environmental chamber monitoring
• Scientific research
• Industrial temperature monitoring
• Electronics thermal testing
• Battery temperature testing
• HVAC testing
• Temperature uniformity studies
• Process monitoring
• Laboratory experiments
• Long-duration thermal testing
• Resistance measurement
• Automated test systems
• Educational and engineering laboratories