
Up to seven observation angles and flexible features
Get up to 7 observation angles and a standard entrance angle allowing for ASTM (-4°) or CEN (+5°) geometry. Supplement entrance angles with 10°, 15°, 20°, 30°, 40°, and 45° extensions.

Upgrade in minutes when needs change
Extend the instrument’s versatility with built-in options for photos of signs, barcode and QR code reader, GPS, instrument rotation and tilt, sign facing direction and MUTCD sign library for automatic pass/fail of sign performance.

Future-ready tablet extension
Use a tablet as an IoT terminal to transfer measured retroreflection data for backup, perform additional analysis, compare data to the MUTCD sign library and more.

Automatic Pass/Fail of sign performance
Automatic color recognition and color contrast (background and legend colors)
Fast calibration with QR code
Download
User manuals for chargers and battery
GRX User manual Bosch charger AL1130CV 230V.
GRX User manual Bosch charger BC330-BC430
GRX Safety information Lithium batteries v5.0
PC software program
RetroSign GRX software pack is the lates approved software version for RetroSign GRX
GRX Software update procedure V2
Choose the right GRX model and adapter
FAQ
What is the difference between RetroSign GRX-1, GRX-3 and GRX-7?
The only difference between the three models is the number of observation angles measured:
- RetroSign GRX-1 measures one main observation angle
- RetroSign GRX-3 measures three observation angles
- RetroSign GRX-7 measures seven observation angles.
The actual observation angle(s) measured depend on the geometry required by the specific standard and is controlled by the angle adapter.
Can a RetroSign GRX-1 be upgraded to a RetroSign GRX-3 or a GRX-7?
Yes, it can, as each RetroSign GRX instrument contains all available features. You can order the upgrade from us by xxx and scan the QR code you receive in the order confirmation email to upgrade.
Can a RetroSign GRX be upgraded with additional features?
Yes, it can, as each RetroSign GRX contains all available features. You can order the upgrade from us by xxx and scanning the QR code you receive in the order confirmation email
Can my RetroSign measure both ASTM (US) and CEN (European) geometry?
Yes, it can. You just need to purchase a second basic angle adapter to cover the other geometry. Each angle adapter will have its own calibration unit at the back of the adapter to calibrate the GRX for this particular geometry.
Can my RetroSign also measure retroreflection of High Visibility Clothing, License plates and Conspicuity Tapes?
Yes, it can. See our price list for an overview of available angle adapter solutions, or contact us for assistance.
How long does it take to measure a road sign?
One retroreflection measurement takes a second independent of the number of measured observation angles.
What is the benefit of measuring three or seven observation angles?
The main observation angle (as measured by RetroSign GRX-1) mainly shows the retroreflection as observed by the driver in a passenger car. The additional observation angles offered by RetroSign GRX-3 and GRX-7 show the retroreflection as seen by a driver in larger vehicles like SUVs, lorries and buses.
What is the benefit of using Point Aperture Geometry over Annular Aperture Geometry?
Point Aperture Geometry ensures accurate readings that replicate real-world driving conditions and correspond to laboratory readings. Point Aperture Geometry enables the user to determine whether a microprismatic sign sheeting material has been applied correctly. See more info about Point Aperture Geometry.
Does the sun affect the measurement result?
No, RetroSign GRX has built-in Stray Light Compensation, effectively ensuring that ambient light from the sun or other light sources does not affect the accuracy of the measurement.
How fast does the battery charge?
The battery is fully charged within 45 minutes.
How many measurements can I perform with a fully charged battery?
This depends on how the instrument is used; LCD backlight use, sound, GPS, printer, and the measurement schedule all influence the achievable number of measurements. A fully charged and standard battery will be able to perform around 800 measurements.
How do we know when to replace the battery?
A fully charged battery will typically perform around 800 measurements. If the number of measurements on a fully charged battery falls below this, it is time to replace it.
How long does a battery last before it needs to be replaced?
This depends on the use pattern. Do not recharge the instrument every time you use it. The battery should discharge between charge cycles to maximise the battery lifetime of several years.
Can I change the battery myself?
Yes, you can. Make sure the instrument is turned off, press on the side of the GRX housing where the battery is located and pull out the battery. Please see the RetroSign GRX Battery instructions.
Can I calibrate the RetroSign GRX myself?
Yes, you can by using the calibration unit located at the back of the angle adapter. Please see the RetroSign GRX Calibration instructions.
How often does the calibration standard need to be re-calibrated?
It can last several years without needing re-calibration if kept dry during storage and taken care of when used, avoiding dirt and scratches on the calibration block surface. We recommend a re-calibration or replacement of the calibration block every two years to ensure correct calibration.
Is there an alternative to sending the calibration unit for re-calibration?
Yes, you can purchase a new calibration unit for your instrument. See our price list for details.
How do I know that the calibration block needs re-calibration or to be changed?
When the calibration block is scratched, dirty and cannot be properly cleaned or otherwise damaged, it is time to replace it.
Does the retroreflectometer itself need to be re-calibrated?
The instrument comes calibrated from the factory. Unless the instrument has been damaged, for instance, by being dropped or run over by a vehicle, it does not need re-calibration.
How often does the RetroSign GRX need to be serviced?
RetroSign GRX is a very robust instrument that can stand daily use without needing service. If an accident happens, like dropping the instrument, we recommend servicing it. If you always want to be sure the instruments work correctly, you can consider an instrument service at regular intervals. If the instrument is used every day, we recommend an annual service. If used less often, a service every 2-3 years will do. Go to RoadSensors Service page
How do I know if/when the instrument needs service?
If the instrument does not work, informs you that it has detected problems in the form of constant errors and/or warnings or the measurements are obviously wrong, the instrument needs urgent service.
Contact
- DELTA - a part of FORCE Technology
Venlighedsvej 4
2970 Hørsholm
Denmark - Tel.: +45 43 25 14 00
- roadsensors@forcetechnology.com
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