The TDHC400 thermochron reader ('Gecko') is a revolutionary way to collect data from a set of thermochron/hygrochron iButton data loggers. It is a pocket-sized device which can read and store the data from up to 1200 thermochrons and then upload them to a PC via a USB connection. Although the iButton is a wonderful way of measuring temperature or humidity discretely and with no overhead, downloading the data has, up until now, required a PC complete with 1-wire adapter and probe. The Gecko allows you to download the data from the iButton and carry it in your pocket ready for upload later when you get back to the office. An ibutton takes between 0.5s and 2s to download its readings to the gecko and is then ready to carry on gathering more temperature data. The Gecko firmware is designed to be field-upgradeable and new firmware will be made available free of charge as necessary.
The Gecko is powered by a rechargeable battery which gives up to 5 days of operation from a single charge. Charging takes place through the USB cable and normally takes 4 - 5 hours for a complete charge. The rechargeable battery is replaceable if necessary. The state of the battery charge is indicated by three LEDs on the front panel.
The Gecko is especially designed to be operated by unskilled staff. Downloading is indicated by the front panel LEDs and if the thermochron has a high or low temperature alarm set then this will also be indicated. There is also an audible indication of download success or failure.
The downloaded thermochron data is stored in flash memory whose contents are retained even if the battery discharges before the data is uploaded to the PC.
The Gecko has an internal clock which may be used to record the time that a reading was downloaded. This makes it suitable for use in applications where an audit trail must be maintained. Each Gecko has also got a unique 64bit serial number which can be read by software and enables the audit trail.
The Gecko is tough and suitable for carrying in a pocket, being about the size of a credit card and weighing less than 50g. Although not waterproof it can be used in moderately damp conditions and can be wiped clean easily. The construction is based around a single PC board with no internal cabling which makes it extremely rugged in operation.
Each Gecko comes complete with a short USB cable, a CD containing basic software that allows the contents to be dumped to a CSV file that can be read by any spreadsheet software, and a strong metal container with a foam insert for easy and safe transportation.
The Gecko data can also be read by software packages from Thermodata Inc (see our software section), which allow iButton data to be uploaded to a database and also allows graphs and charts to be plotted.