Eartag units have been used as an attachment method on animals with changing neck girth (i.e.
juveniles, buck deer, and some bears) where a collar may not be suitable. These eartag units are
constructed using a high impact plastic housing that supersedes the water resistance of older
designs using epoxy and acrylic resins as a moisture barrier.
Two basic designs, employing two different form factors, are available.
The ET-5 and ET-6 are designed as a "button" and the antenna penetrates the ear pinnae and exists
out the back of the ear. This design approach uses an electrically foreshortened antenna that
avoids the longer "droopy" antenna used in some other designs. The button design allows the
transmitter to rotate freely, again minimizing irritation and infection at the attachment site.
These eartags were originally designed for use on polar bears, but the design is suitable for use
on other species of bear, and on ungulates.
A more classical approach in the design is used in the ET-7 configuration. In this design approach
the electronics unit is attached to a standard eartag used extensively throughout the livestock
industry. This approach allows for rotation of the eartag about a single attachment point, but in
general the weight of the electronics package keeps that part of the configuration near the base
of the ear and the antenna up and away from the animal's eye. This design approach is often
favored for attachment to ungulate species. A classical whip antenna design is employed and
attachment is accomplished quickly in the field.
Eartag configurations that have exposed antennas may have the damaged due to by other animals or
mechanically damaged when the animal lives is in thick cover. Antenna breakage can occur and
result in reduced range performance over time.
As a note both designs require special attachment tools
which can be purchased separately.
Key Features
- Offers an alternative to other attachments such as collars.
- Used on juvenile animals during periods of rapid growth.
- Programmable duty cycling can extend the operational life of the unit.
- Specialized attachment tools are available for applying the tag.
- Numerous sensor options i.e. mortality sensing are available.
- Excellent range performance with the selection of various power level options.
Models
| Configuration |
Dimensions (in, cm) |
Unit Weight (g) |
Operational Life @ 60 BPM (months) |
Operational Life @ 35 BPM (months) |
Transmitter Electronics |
Microprocessor Control Options |
| ET-5 |
0.83 x 1.38
2.1 x 3.5 dia |
40 |
4.1 |
6.6 |
MK8 |
MS6, MA, MS9, MDC, MS4, MS5 |
| ET-6 |
1.06 x 1.38
2.6 x 3.5 dia |
50 |
8.2 |
13.3 |
MK8 |
MS6, MA, MS9, MDC, MS4, MS5 |
| ET-7 |
1.55 x 0.95 x 0.70
3.94 x 2.41 x 1.78 |
27 |
5.8 |
9.4 |
MK8 |
MS6, MA, MS9, MDC, MS4, MS5 |
Specifications for Transmitter Electronics
MK8 Transmitter General Specifications
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The MK8 Transmitter is a single frequency, microprocessor controlled pulsed-CW transmitter,
designed for operation in the 140 - 220 MHz frequency range.
| Frequency Range |
140 - 220 MHz |
| Frequency Tolerance |
±17 ppm max @ 25°C
±25 ppm max -40°lC < Temp < +60°C
(<7ppm typical w/ variation in load impedance - 6:1VSWR)
(<3ppm typical over supply voltage range at room temperature)
|
| Temperature Range |
-40°C to +60 °C (Note: Temperature range is for the transmitter only. The power supply
must provide the required peak current and voltage requirements for the transmitter over the
expected temperature range.)
|
| Shutdown Component |
Externally shutdown by presence of a small magnet |
| Output Power |
| Output Power Option |
Peak Power Output Levels
Relative to Standard Power |
| Low |
0.5 x |
| Standard |
1 x |
| High |
2 x |
| Extra high |
5 x |
|
| RF Pulse Width |
15 msec standard
Can optionally be configured from 12 - 255 msec
|
| Pulse Period |
Configurable from 200 - 10000 msec (6-300 Bpm) |
| Spurious Emissions |
Non-coherent Spurs <-50 dBc |
| Harmonic Suppression |
Coherent Spurs <-10 dBc |
| Available Sensors |
Motion (Hg switch - activity/mortality) - options MS6, MA
Position (Hg switch - head up/head down) - option MS9
Temperature Triggered Mortality Sensor - option MS5
Temperature Measurement Sensor - MS4
| Option |
Resolution at standard center temperature of 37°C |
Calibrated Accuracy |
| MS4-400 |
0.4 deg |
±(0.6°C + cal. uncertainty*)
±20°C from center temperature
|
| MS4-400 |
0.4 deg |
±(0.9°C + cal. uncertainty*)
±40°C from center temperature
|
| MS4-410 |
0.1 deg |
±(0.15°C + cal. uncertainty*)
±10°C from center temperature
|
*(Note: "Cal. uncertainty" is the error inherent in the calibration procedure. This value is
dependant on the end users calibration procedure and equipment accuracy.
For example, if the calibration process measures temperature to within ±0.1°C, then the
MK8 calibrated accuracy would be:
- For 0.4 deg resolution option
±(0.6deg + 0.1deg) = ±0.7degC (±20°C)
±(0.9deg + 0.1deg) = ±1.0degC (±40°C)
- For 0.1 deg resolution option
±(0.15deg + 0.1deg) = ±0.25degC (±10°C)
|
| Seasonal Timing |
8 factory programmable on-off duty cycles - option MDC
Typical timing accuracy of < ± 30 min/yr is reasonable for most applications
Chart reflects known error limits
| Temperature (°C) |
Error Limits (min/yr) |
| -40°C |
~ -73 to -105 (extrapolated) |
| -20°C |
-25 to -58 |
| 0°C |
2.6 to -29 |
| 25°C |
±16 |
| 50°C |
2.6 to -29 |
| 70°C |
-25 to -58 |
|
| FCC Emission Designator |
1k00P0N * California Users - The MK8 transmitter exceeds the emission designator
requirement of 2k00P0N for operation in California. The MK8's 1k00P0N emission
designator is identical to 2k00P0N except that it occupies only half of the 2 kHz
bandwidth allowed by the State of California for wildlife tracking.
|
Conventional Control Options
Mortality (S6A, S6B) and activity (S9) sensors are available with all eartag configurations.
VHF Transmitter Sensor Option Descriptions
An increased operational life may be achieved with the use of a microprocessor to establish a
transmitting duty cycle. Microprocessor controlled transmitters provide capabilities beyond those
offered by any other conventional VHF transmitter designed for tracking and/or wildlife
monitoring. These new capabilities include MDC duty cycling (turning transmitters on and off at
predetermined intervals), and MA transmission of activity indices. More traditional options such
as MS6 mortality sensing and MS9 activity sensing remain available, but with increased flexibility.
MK8 Microprocessor Control Sensor Options
Show
| Opt. MDC MK8 Duty Cycles |
Transmitters can be programmed to cycle through up to eight sequential time periods
or "duty cycles" in order to extend transmitter life. Within each duty cycle, the
transmitter can either be "on" or "off". Pulse rates can be uniquely defined for each "on"
duty cycle. Each duty cycle can be defined from eight seconds to approximately 50 months in
length. Duty Cycle timing begins at the moment the magnet is removed to initialize the
transmitter. Upon completion of the last programmed Duty Cycle Period, the transmitter
begins again at the first duty cycle. |
| Opt. MA Activity Sensor |
Varies the pulse period depending on the relative activity level of the animal. A
motion-sensitive switch detects animal movements and the microprocessor monitors changes in
the state of the switch (open vs. closed). A user-defined evaluation time is established and
the number of switch state changes is recorded by the microprocessor. The maximum number of
state changes is limited to one per second by the software. The transmitter pulse period
varies between two user-defined pulse periods. One pulse period corresponds to "no activity"
and the other corresponds to a user-defined "maximum activity level". A graph supplied with
the transmitter correlates activity level and pulse period. |
| Opt. MS4 Temperature Sensor |
Monitors body temperature in proximity to the collar on the animal (pulse period varies
with temperature). User may define the desired pulse period vs temperature characteristic of
the transmitter (contact factory for details). Standard temperature resolution is
approximately 0.4°C. Optional high-resolution circuitry provides approximately 0.1° C
resolution.
The MS4 temperature sensor circuitry provides accurate temperature measurements, even when
the transmitter cannot be recovered and recalibrated after period of data collection. This
virtually eliminates calibration drifts due to aging and battery voltage changes over
time. |
| Opt. MS5 Temperature-Triggered Mortality Sensor |
This option determines a mortality event in an endothermic animal with a stable body
temperature. Faster (mortality) pulse rate is triggered when body temperature drops below a
user specified temperature.
Note: Pulse rate is returned to original rate if temperature rises back above the specified
temperature. Consideration of the ambient temperature is a consideration in selection of the
transition threshold. For example, temperature-controlled sensors would probably not be
suitable in areas where high ambient temperatures would prevent rapid cooling of body after
death. This option is often used in monitoring waterfowl mortality events where motion
sensitive mortality sensors may not be applicable (e.g. where the body may continue to be
rocked by waves on the surface of a lake). Available in all implant configurations. Please
contact the laboratory to discuss implementation of this sensor before ordering. |
| Opt. MS6 Mortality-Motion Sensor |
Provides "active or alive" or "inactive or dead" pulse period depending on activity
state of the study animal. A motion-sensitive switch is incorporated in the unit to detect
animal movements. The microprocessor continuously monitors the motion switch to determine
when motion occurs. Once per second, the microprocessor increments an "activity counter"
if motion was detected during the preceding one-second time period. This "activity counter"
keeps a running total of the number of times motion was detected over a user-defined
mortality evaluation time (8 sec to 6 days). The active pulse period is maintained as long
as the number of switch closures in the mortality evaluation time is greater than the
mortality threshold. If the number of switch closures falls below the established threshold,
the unit produces the inactive period. A separate resurrection threshold allows the unit to
return to the active pulse period if the number of activity counts during the mortality
evaluation time exceeds the resurrection threshold.
Note: The microprocessor updates the active/inactive pulse period at intervals of 1/16th of
the evaluation time. This means that after the "resurrection" threshold criterion is met,
there will be a delay of up to 6.25% of the evaluation time before the transmitter reverts
to the "active" pulse period. The same is true with the transition between "active" and
"inactive" pulse periods. The actual time between cessation of motion and initiation of the
"inactive/dead" pulse period can be up to 6.25% longer than the evaluation time. |
| Opt. MS9 Tip Switch Sensor |
Transmits one of two different pulse rates depending on orientation of the transmitter.
Usually designed to switch pulse rates as it passes through an angle of 0° (parallel to
horizontal). Other switching angles may be selected with some configurations (factory set
within 10°).** Typical uses include monitoring "head up" and "head down" positions. |
 |
FX005053-001 Eartag Attachment Tool for ET-5 |
 |
FX005053-002 Eartag Attachment Tool for ET-6 |
 |
FX006525-001 Eartag Attachment Tool for ET-7 |
