The PT-104A is a four-channel, high-resolution temperature data
acquisition module for use with PT100 and PT1000 RTD sensors.
It can also be used to measure resistance (375 Ω and 10,000 Ω
ranges) and voltage (115 mV or 2.5 V ranges). In PT100/PT1000/
resistance mode, the unit uses a four wire circuit. In voltage mode,
the input connector can be treated as a differential input with ground,
or two single-ended inputs. Both inputs must be 0V or above, though
it does not matter which input has the higher
Although accurate temperature sensors are widely available, it has
been difficult to take advantage of them due to errors caused by the
measuring device. The PT-104A, however, is designed to be inherently
accurate. Rather than relying on voltage references (which tend to be
temperature sensitive) it uses ‘reference’ resistors which are
extremely stable (low temperature coefficient and drift). The exact
value of each resistor is stored in an EEPROM to provide the ultimate
in accuracy (yearly re-calibration is recommended). To achieve
the 0.001°C resolution a highly advanced ADC is used that can
resolve to better than 1 part in 16 million.
The PT-104A measures temperature using platinum resistance
temperature sensors (RTDs). Both common industry standards (PT100
and PT1000) are supported. The unit is compatible with 2, 3 and 4 wire
sensors (4 wire PT100 sensors are recommended for accurate
When measuring resistance, the unit uses a four-wire circuit to give the
greatest possible accuracy. Two resistance ranges are available
(0 to 375 Ω and 0 to 10,000 Ω). The unit is calibrated for 0 to 375 Ω
so this range should be used for accurate measurements.
For voltage measurements, each input connector can be treated as
a differential input with ground, or two single-ended inputs.
Both inputs must be zero volts or above, though it does not matter
which input has the higher voltage. Two voltage ranges are available
(0 to 115 mV and 0 to 2500 mV). For the most accurate
measurements use the 0 to 2500 mV range.
For the 115 mV voltage range, the accuracy may vary by 2%,
and the temperature coefficient will be 100 ppm/°C.
Remote Data Collection
The new USB/Ethernet interface allows the device to be used in a
variety of situations: USB-only, USB powered
with Ethernet data, and Ethernet data with Power-over-Ethernet (PoE). Using the Ethernet interface, the PT-104A can
be located anywhere on a LAN or on the internet.
Power over Ethernet (PoE)
The PT-104A can obtain its power from the Ethernet port as a Powered
Device (PD) according to the PoE standard. To use this feature, you must
connect the unit to Power Sourcing Equipment (PSE) such as a network
switch, router or power injector that also supports the PoE standard. Any
standard Ethernet cable up to 100 metres in length can be used.
The PT-104A is supplied with Windows Logging and Player
Software. The software will automatically detect which sensor is
connected and will display readings in the correct units. Also
supplied is a software development kit (SDK).
The SDK contains a range of software drivers and example code
that you can use to write your own software or to use your PT-104A
device with third party software. With the included Logging Software
you can set the sampling interval from 1 second to several hours and
set the maximum number of readings. You can also tell the
PT-104A data acquisition module what do to when the temperature
readings have been taken—either: stop; repeat immediately (start
again); scroll (oldest recordings disappear); or repeat after delay
(where the delay is set by the user). Multiple PT-104A modules can be
used simultaneously with the logging software. Also, PT-104A
modules can be mixed with TC-08 thermocouple input modules and
used at the same time. Up to 20 units of any kind (PT-104A or
TC-08) can be connected.Using the PT-104A logging
software, data can be viewed in a spreadsheet and/or in a graph as it
is being recorded. Data collected from previous recordings can also
be viewed using the Player.
† All amounts shown in EUR, GBP, or USD Note: Includes USB cable, Ethernet patch cable, 4 mating mini DIN screw terminal connectors, quick start guide, Windows software and complete operator’s manual on CD.