Quick Answer
What is the Trimble SNR941?
See also: Trimble GCS900 Grade Control System
See also: Spectra Precision HL760 Laser Receiver
The Trimble SNR941 is a machine-mounted grade rod and laser receiver system that augments the GCS900 GNSS machine control system with laser plane detection, achieving 3mm vertical accuracy for finish grading on flat surfaces.
Trimble SNR941 — Complete Specs, Manual & Guide
Category: Machine Control Grade Rod | Brand: Trimble | Model: SNR941
The Trimble SNR941 is a machine control grade rod designed to integrate with the Trimble GCS900 system. Mounted on the machine's blade mast, it detects the rotating laser plane and feeds elevation data into the GCS900 CB460 display. In laser augmentation mode, the GCS900 uses laser elevation data instead of GNSS for vertical control, reducing vertical uncertainty from 20mm to approximately 3mm for finish grading on flat sites.
Trimble SNR941 Full Specifications
| Vertical accuracy (laser mode) | ±3mm |
| Detection band height | 165mm |
| Laser detection range | Up to 600m from laser source |
| Compatible systems | Trimble GCS900, Earthworks |
| Compatible lasers | Spectra Precision rotating lasers, most 635nm lasers |
| Rod length | Adjustable — standard machine mast heights |
| Power supply | 12VDC from machine electrical system |
| Output | Digital grade control signal to GCS900 CB460 |
| Operating temperature | -40°C to +65°C |
| IP rating | IP67 |
GCS900 Laser Augmentation Mode
- GNSS provides horizontal control — X/Y position from GNSS stays active
- Laser provides vertical control — elevation from rotating laser replaces GNSS Z
- Automatic switching — system reverts to GNSS if laser signal is lost
- Best application — flat finish grade pads, parking lots, airfields
Frequently Asked Questions — Trimble SNR941
How does the SNR941 improve GCS900 accuracy?
In GNSS-only mode, the GCS900 achieves approximately 20mm vertical accuracy. Adding the SNR941 in laser augmentation mode reduces vertical uncertainty to ±3mm by deriving elevation from the rotating laser plane, which is inherently more stable than GNSS vertical signals affected by ionospheric variation.
Is the SNR941 required for the GCS900 to work?
No. The GCS900 operates in full 3D mode using GNSS alone without the SNR941. The grade rod is an optional accessory that improves vertical accuracy for finish grading applications. Many users add the SNR941 only for final grade passes.
What lasers work with the SNR941?
The SNR941 is designed for Spectra Precision rotating lasers (LL300, GL722) but also detects most standard 635nm rotating lasers from other manufacturers in passive detection mode. For best results, use a self-leveling horizontal laser on flat grade work.
Can the SNR941 be used on a grader as well as a dozer?
Yes. The SNR941 is compatible with both dozers and motor graders equipped with the GCS900 system. Mounting configurations differ by machine; Trimble provides machine-specific mast and bracket kits for each application.
Related models: Trimble GCS900 | Spectra HL760
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