Mk9 Archival Tag
The Mk9 archival tag is designed to study seals, penguins, fish and other marine animals. The Mk9 measures depth, temperature, and light-level, and also differentiates wet or dry conditions. It is suitable for both external attachment and internal implantation.
The standard Mk9 configuration has the depth, temperature, light-level and wet/dry sensors mounted on the body of the tag, and comes with 64 Mbytes (minimum) data storage. Optionally, for implantable applications, the light level and/or a second temperature sensor can be mounted on a sensor stalk. A third option is an external fast-response thermistor, mounted on the body of the tag.
Direct U.S. prices start at $950 for the three standard configurations shown on the Mk9 product page. Please contact us for pricing on other configurations.
Controller features
The operating code of the Mk9 can be upgraded. This means you can always have the most up-to-date version of on-board software, regardless of when the tag was purchased. The low-voltage design minimizes power consumption to extend battery life. The onboard clock is temperature-corrected over the range -20°C to + 50°C to provide high time accuracy throughout the deployment. Clock correction is active even when the Mk9 is in stand-by mode.
Sensors
The Mk9 is configured with multiple sensors.
Depth
A 12-bit analog-to-digital converter is used, which provides highly-accurate measurements from -40 to +1000m, with 0.5m resolution and an accuracy of ± 1%. In addition, measurements from 1000 to 1500m are made with a lesser degree of accuracy. Measurements can be recorded throughout the range at full resolution. Two bytes of memory are required to store depth readings in this uncompressed mode.
Temperature
A 12-bit analog-to-digital converter is used, which provides an actual measured range of -40° to +60°C, with 0.05°C resolution and an accuracy of ±0.1°C. Measurements can be recorded throughout the range at full resolution. Two bytes of memory are required to store temperature readings in this uncompressed mode.
Both depth and temperature sensor readings can be compressed to fit into one byte of memory. Up to 16 million readings can be stored in compressed mode.
Light-level
The light sensor has a logarithmic range from 5 x 10-12 W.cm-2 to 5 x 10-2 W.cm-2. Bright sunshine is approximately 2 x 10-3 W.cm-2. Tests have shown the sensor to be able to identify dawn/dusk events down to 300m in clear waters.
Wet/Dry
The Mk9 can be configured with a sensor which allows the user to set the tag to sample only when wet and to keep track of the time when it is dry.
User-programmable sampling protocols
Sampling is controlled by a user-specified sampling protocol. The user programs the rate at which each sensor is sampled, and whether or not sampling is suspended when the wet/ dry sensor reads dry.
Memory and data retention
64 Mbytes of non-volatile Flash memory for data storage allows the Mk9 to store 32 to 64 million samples (sensor readings). Each sample occupies either one or two bytes of memory, depending upon the resolution selected. 8.7 years of data can be stored when sampling depth, tag temperature, stalk temperature and light-level every 30 seconds at full resolution. Data are maintained in memory for more than 25 years even if the battery is exhausted.
Battery life
Efficient power management is attained by using a low-voltage micro-controller and flash memory. Actual battery life is dependent upon the sampling regime and temperature conditions. Under most deployment conditions, the battery can be expected to provide enough power to fill memory at least 5 times. Batteries can be replaced for extended instrument life.
Communication
The Mk9 can be configured with a sensor which allows the user to set the tag to sample only when wet and to keep track of the time when it is dry.
Tag activation
The Mk9’s can be turned on and off with a magnet. The LED flash sequence indicates whether the tag is in standby or deployed.
Size, weight and pressure resistance.
The standard external configuration is 67mm long by 17mm by 17mm, weighing 30g or less (in air). The standard implant configuration is 73mm long by 18mm in diameter, weighing 30g or less (in air). These configurations will withstand up to 1000m of pressure. Other configurations are available for both implantation and external application for depths to 2000m. Actual dimensions and weights are subject to change, so should be verified at the time an order is placed.
Surface materials.
The main body of the instrument is hydrolytically stable and non-biologically reactive.
Geolocation using light-level
Wildlife Computers has developed software, WC-GPE, that calculates daily longitude and latitude from recorded light level curves. Longitude accuracy can be as good as ±0.5 degrees. Latitude accuracy depends upon both the latitude and time of the year. Best accuracies (±1 degree) are achieved at high latitudes near the solstices, and worst occur near the equator near the equinoxes (±10 degrees, where and when latitude can be calculated).
Data decoding and analysis
Wildlife Computers-designed PC-based software is available to aid in the analysis of the data.
All Mk9 tags are built-to-order
Stress testing and sensor calibration are performed after the instrument is cast, and each unit is bench-tested prior to shipment to confirm sensor calibration and proper functioning.
Tag customization
Custom modifications, including changes to the sensors and shape of the packaging may be available. For example, the Mk9 can be configured to support up to three temperature sensors; it can be configured to accept input in the 0 to 2.5V range from a user-supplied sensor; and larger memory configurations are available.
For custom orders, please contact Wildlife Computers to determine availability. Lead times for such orders may be significantly longer than standard.
Specifications are subject to change.
