Huliwai (HD)

The HD version of the huliwai is capable of measuring temperature and pressure for over four months at eight measurements per second. It is self-contained with sensors and data logger integrated in one waterproof package.

Compare to the standard version, the HD version has a larger data memory and higher max. measurement rate, but no light measurement capability. Communication requires a USB-to-serial adapter as it has no infra-red communication interface. The temperature and pressure sensors are other the same.


Variable Metric Value Unit Condition Note
Temperature Range [0,40] °C - Non-freezing.
Accuracy +/-0.1 °C - -
Resolution 16 or 24 bit - Configuration-dependent.
Pressure Range [0,30] Bar - Roughly 300 meters.
Accuracy 100 mBar - -
Resolution 0.5 mBar - -
Sampling Interval - {1/8, 1/4, 1/2, 1} Second - User-configurable.
Endurance - 4 Month 2xAA alkaline cells. Battery-limited.
- 6 Month 2xC alkaline cells; 1/8s interval. Memory-limited. Custom battery pack required.

Note: Endurance tests were conducted with off-the-shelf alkaline cells (e.g. Energizer EN91 for AA). Lithium primaries such as Energizer L91 typically last ~30% longer.


The logger has a serial (TTL) interface for configuration and data transfer. A USB-to-serial adapter is used to communicate with the loggers from a computer. This requires opening the housing for access to the logger circuit.


The logger can be configured with 2x AA or C cells. The logger has battery holder for AA cells by default. To use C cells for the extended endurance, a custom battery pack and an alternative chassis are required.

More info coming soon...