Series-WTDL

Supported Applications

The Series WTDL Wireless Temperature/Humidity Data Logger is designed for real-time monitoring and for areas that are not easily accessible for periodic retrieval. Data loggers transmit up to 500 ft indoors and up to 2000 ft outdoors, and the distance can be increased by using additional receivers. Wireless data is transmitted on a 2.4 GHz frequency, allowing the system to be used globally.

A network of loggers can be built up and monitored from a PC through a wireless transceiver, and the system can send text and email alarm updates when readings move out of range. This makes the series well suited to monitoring refrigerators, freezers, ovens, warehouses, and other locations where running cabling would be impractical. The battery is user replaceable with a typical life of two years; because shorter sample rates considerably shorten battery life, the longest practical sampling rate is recommended.

Operating Conditions & Performance

The internal sensor measures -4 to 176°F (-20 to 80°C), while the WTDL-30 probe extends measurement to -328 to 500°F (-200°C to 260°C). Humidity is measured over 0 to 95% RH on the humidity-equipped model. Temperature accuracy is 0.9°F (0.5°C) from 32 to 122°F (0 to 50°C) and 0.18°F (0.1°C) from -4 to 176°F (-20 to 80°C), with a temperature resolution of 0.018°F (0.01°C). Humidity accuracy is ±3.0% RH (±2% typical at 77°F (25°C)) with 0.1% RH resolution on the humidity model.

Wireless data is carried on a 2.4 GHz RF frequency within the 2.405 to 2.48 GHz ISM band, with a maximum power output of +0 dBm typical and a receiver sensitivity of -95 dBm typical. Sampling can be set to stop on memory full or to continuous recording. Power is supplied by a user-replaceable 3.6 V TL-5104 lithium metal battery, and the logger connects to a PC through a mini USB port for setup. The housing is ABS plastic and the loggers are FCC approved and CE marked.

The wireless network is served by the WTDL-RX transceiver, which can act as a repeater or connect directly to a PC by USB, operates on the 2.4 GHz band, and supports communication with up to 64 data loggers. The transceiver has an IP40 rating and is rated over -20°C to 85°C; it is not water resistant, and for best performance its external antenna should point straight up.

Configuration Options

The two models share the same wireless platform but differ in what they sense:

• WTDL-20 is a temperature data logger with humidity output. It adds relative humidity measurement over 0 to 95% RH, and the humidity accuracy and 0.1% RH resolution apply to this model.
• WTDL-30 is a temperature data logger with a probe attachment. The external probe greatly extends the temperature span to -328 to 500°F (-200°C to 260°C), suiting oven, freezer, and process points that exceed the range of the internal sensor.

Both models use the same 2.4 GHz radio, 0.018°F (0.01°C) temperature resolution, user-replaceable battery, and mini USB interface, and both work with the shared WTDL-RX transceiver and PC software.

Key Product Differences

The Series WTDL is offered in the following models:

• WTDL-20 — temperature data logger with humidity output.
• WTDL-30 — temperature data logger with probe attachment.

Supporting items include the WTDL-RX wireless transceiver (supplied with a USB cable, software CD, software manual, and A/C adapter) and the TLH-5903 replacement battery.