High accuracy PT-104 PRT to PC converter

Edited by the Engineeringtalk editorial team Dec 28, 2000

Pico Technology has announced the PT-104, a high resolution, high accuracy four-channel temperature-measuring device which can be used with both industry standard PT100 and PT1000 PRTs

Pico Technology, specialists in PC-based instruments, has announced the PT-104, a high resolution, high accuracy four-channel temperature-measuring device.

The PT-104 measures temperature using platinum resistance thermometers (PRTs) and can be used with both industry standard PT100 and PT1000 PRTs.

In addition, when used with PT100 sensors, the PT-104 offers the ultimate in resolution (0.001 degrees C) and accuracy (0.01 degrees C).

The converter can also be used to measure resistance and voltage, and affords remote access/interrogation.

Mike Green, Pico Technology's Managing Director comments: "Although accurate temperature sensors are widely available, before now it has been extremely difficult to take advantage of them due to errors caused by the measuring devices.

The PT-104 however is inherently accurate due to its novel design." Rather than relying on voltage references (which tend to be temperature sensitive), the PT-104 employs 'reference resistors'.

Green explains: "These resistors are extremely stable: low temperature co-efficient and low drift.

The exact value of each resistor is stored in EEPROM to provide the ultimate in accuracy.

To achieve the 0.001 degrees C resolution when used with PT100 sensors a 24 bit ADC is used that can resolve better than 1 part in 16 million.

The unit is compatible with 2, 3 and 4 wire sensors, though 4 wire PT100 sensors are recommended for applications demanding the highest accuracy.

In addition to measuring temperature, the PT-104 can also measure resistance and voltage.

Two resistance ranges are available (0 to 375 ohms and 0 to 10Kohms).

For voltage measurements, each input connector can be treated as a differential input with ground, or as two single ended inputs.

Both inputs must be 0V or above, though it does not matter which input has the higher voltage.

Two ranges are available (0 to 115mV and 0 to 2500mV).

The PT-104 is supplied with PicoLog software for advanced data logging.

"PicoLog will automatically detect which sensor is connected and will display readings in the correct units," continues Green.

"And for users who wish to write their own custom software, drivers and examples are supplied with the PT-104." The PT-104 is normally connected directly to a PC, but it is also possible to communicate with the PT-104 using a modem (radio or telephone) so that users can collect data from a remote site.

"This is a real bonus for users with remote measurement requirements," concludes Green, "and with the ability to measure voltage and resistance, the PT-104 PRT to PC converter is an invaluable data acquisition tool." A range of sensors for the PT-104 is available from Pico Technology in various accuracy ratings and packages to suit most applications.