Description
Haglof Sweden T4 Transponder
Ultrasonic Reference Unit for Precision Measurement
The Haglof Sweden T4 Transponder is a high-quality ultrasonic transmitter/receiver designed to work seamlessly with Vertex instruments, Vertex Laser Geo, and older compatible models. Available from Prospectors Supplies, it enhances height, distance and angle measurements by serving as a reliable reference point in the field, especially when line of sight is obscured or when working in dense vegetation. The T4 replaces older transponders with updated electronics, better battery flexibility and improved user feedback features, making it a practical upgrade for professionals who demand precision and durability.
When active, the T4 emits ultrasonic pulses that the measuring instrument uses to determine accurate distances, enabling height and slope calculations via trigonometry. It can operate in standard direct measurement mode (≈60° aim) or full 360° measuring when used with the 360° adapter, which is especially useful for circular sample plots. Six built-in LEDs provide instant visual feedback—indicating whether the unit is active, responsive, detecting noise interference, or experiencing signal issues—so you can quickly assess if conditions are ideal for measurement.
The housing has been improved to accommodate any brand of 1.5 V AA battery, offering longer runtime and easier battery sourcing in field conditions. The T4 is fully backwards compatible, meaning existing equipment using older transponders (like T3) can be upgraded without having to replace whole systems. Lightweight, robust and easy to carry, it is built for demanding Australian conditions and field workflows.
Key Features
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Replacement for older transponders (T3 and previous) with improved electronics and housing
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Operates in direct measurement mode (~60°) and 360° mode when paired with the 360° adapter
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Six-LED indicator panel for status, responsiveness and detecting disruptive noise
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Compatible with any 1.5 V AA battery—useful in remote or field situations where native battery packs are unavailable
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Works with Vertex 5, Vertex Laser Geo, DME instruments, and older Vertex/T-series models
Specifications
| Parameter | Specification |
|---|---|
| Diameter | ~70 mm |
| Weight (incl. battery) | ~85 g |
| Battery | 1 × AA 1.5 V alkaline |
| Power Consumption | ~9 mW |
| Operating Duration | Approx. 20 minutes active time per activation |
| LED Indicators | 6 LEDs (status, signal, noise etc.) |
| Modes of Operation | Direct (~60°), 360° with adapter |
| Compatibility | Fully compatible with older Vertex/T-series & newer Vertex, GEO, DME instruments |
Applications
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Using as a reference point for measuring tree height, especially where direct line of sight to the top of a tree is not possible
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Sample plot work requiring full 360° transponder measurement
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Survey, forestry or environmental field work under canopy or dense vegetation
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Upgrading older transponder systems to improve measurement reliability and user feedback
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Utility and forestry checks where accurate distances are needed from a fixed reference
Why Choose Prospectors Supplies
At Prospectors Supplies we recognise that accurate, durable tools matter in the field. Choosing the Haglof Sweden T4 Transponder through us means you’re buying more than just hardware—you also get advice borne of field experience, support for setup and compatibility, and after-sales service from people who understand what precision in measurement really requires. We aim to ensure your work is more consistent, efficient and reliable wherever you are measuring.
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