Why This Instrument
The YMP-25 Yellow Mini Prism is designed for surveyors who need a practical field target that is easy to carry, quick to sight and accurate enough for demanding setout and monitoring tasks. Its 25 mm precision reflector supports reliable measurement up to 500 m, making it useful for construction crews, rail teams and civil surveyors working across Australian project sites.
This model is particularly suited to construction setout and monitoring applications where visibility, mounting flexibility and consistent prism constants matter. Compared with general-purpose mini prism targets, the YMP-25 is a stronger option for control and traverse work when a compact precision reflector is required.
What Sets It Apart
- 25 mm precision mini prism: Provides a compact optical target for accurate EDM measurements on construction, civil, rail and engineering survey work.
- Up to 500 m working range: Supports practical distance measurement across medium-range setout, monitoring and topographic survey tasks without needing a larger prism.
- High-visibility yellow housing: Helps field crews locate and sight the target faster on active construction sites, rail corridors, tunnels and busy civil environments.
- Leica and Trimble prism constants: Supports Leica +17.5 mm and Trimble -16.9 mm constants, helping surveyors apply the correct offset for accurate total station measurement.
- Copper or silver coated reflector options: Allows surveyors to select the reflector coating that best suits their instrument setup and measurement requirements.
- Lightweight 115 g design: Reduces load for handheld work and makes the prism easier to position during repeated setout, monitoring and topographic survey tasks.
- Leica spigot or 5/8-inch mounting options: Gives crews flexibility to mount the prism on compatible poles, brackets or monitoring setups depending on the site workflow.
- Robust construction for site use: The durable housing is suitable for civil, construction, rail and infrastructure environments where equipment is handled frequently in the field.
| Product | L-Bar Monitoring Prism |
| Part Number | MP110W |
| Prism Type | Monitoring prism with copper or silver coating options |
| Prism Diameter | 25 mm |
| Primary Use | Rail track and corridor monitoring, tunnel convergence monitoring, bridge movement monitoring, retaining wall monitoring, building settlement monitoring, mining deformation monitoring, landslide and slope stability monitoring |
| Measuring Range | Up to 2,000 m, depending on total station, site setup and environmental conditions |
| Prism Constant — Leica | +9 mm |
| Prism Constant — Trimble | -25.4 mm |
| Weather Protection | Available in dustproof or waterproof configuration |
| Overall Height | Approx. 89 mm |
| Installation Type | Permanent monitoring target |
| Compatible Workflows | Deformation monitoring, structural monitoring, automated monitoring systems, robotic total station observations and repeat fixed-point surveys |
| Instrument Compatibility | Compatible with Leica, Trimble and Topcon total stations when the correct prism constant and instrument settings are applied |
What’s Included
- MP110W L-Bar Monitoring Prism
- Selected reflector coating: copper or silver
- Selected weather protection option: dustproof or waterproof configuration
Package contents may vary depending on the selected coating and weather protection option. Contact Terra360 before ordering if you need to confirm the correct configuration for rail, tunnel, bridge, mining, slope or structural monitoring work.
Works With
The MP110W L-Bar Monitoring Prism works with total station and automated monitoring workflows used across Australian rail, civil, mining, construction and infrastructure projects, including:- Leica total stations using the correct +9 mm prism constant
- Trimble total stations using the correct -25.4 mm prism constant
- Topcon total stations with the correct user-applied prism constant
- Robotic total stations used in automated monitoring systems
- Rail track and corridor monitoring programs
- Tunnel convergence monitoring setups
- Bridge movement and structural deformation monitoring
- Mining deformation, landslide and slope stability monitoring
Using the correct prism constant is essential for accurate monitoring data. For Leica instruments, apply +9 mm. For Trimble instruments, apply -25.4 mm before starting observations.
Australian Support
Terra360 supplies survey and monitoring equipment for Australian rail, civil, mining, construction and infrastructure teams, with local support before and after purchase. The MP110W L-Bar Monitoring Prism is backed by the applicable Australian warranty terms for this product, with Terra360 acting as your point of contact for warranty, compatibility and product support.
For help confirming prism coating, weather protection, prism constants or robotic monitoring compatibility, contact Terra360 before ordering.
Frequently asked questions
The MP110W is best used for rail track and corridor monitoring, tunnel convergence monitoring, bridge movement monitoring, retaining wall monitoring, building settlement monitoring, mining deformation monitoring, landslide monitoring and automated robotic total station monitoring systems.
Yes. The MP110W is suitable for automated monitoring systems using robotic total stations where fixed targets need to be measured repeatedly over time.
Use a +9 mm prism constant when using the MP110W L-Bar Monitoring Prism with Leica total stations.
Use a -25.4 mm prism constant when using the MP110W L-Bar Monitoring Prism with Trimble total stations.
The MP110W supports measurements up to 2,000 m, depending on the total station, site setup, visibility and environmental conditions.
Choose dustproof protection for dry, dusty or mining-style environments. Choose waterproof protection for exposed outdoor monitoring locations where rain, moisture or wet conditions are expected.