Goniophotometer FAQs

Overview Questions

1. How many similar systems are currently in service worldwide?

STS currently services machines in the United States and overseas. Owner Michael Piscitelli has worked in this industry for 17 years, and has designed/installed/built/supported approximately 60 goniometer systems in those years.

2. Does the machine test both Photometrics and Chromaticity? Can it conduct these tests at the same time? What kind of sensor is used to detect chromaticity?

The machine can test chromaticity if you were to purchase the AP-OPT-002 option. The "sensor" is a Compact Spectroradiometer that is controlled by the goniometer software and can also be used separately as a portable device for both luminance(radiance) and illuminance(irradiance) measurements.

3. How long does it take until the machine is installed and ready to be used?

Once the machine is ordered, it typically takes 12-16 weeks to complete the job. Most of this time is the lead time on large components such as gearing, etc. that we not keep in stock due to the fact that these are "made-to-order" devices. No one that we know keeps goniometers "in-stock." We can supply one more quickly if the parts are available.

4. What is the size of your machine? Can it be adapted to fit space constraints?

The machine has a footprint of 55 inches left to right and 35 inches front to back. In order to move fully through its operational travel, the machine needs approximately 6 feet left to right and 5 feet from front to back. The frame itself can be "shortened" from left to right, however that would limit the clear turning circle to a smaller diameter. Right now a 48 inch diameter is possible with an AP-"48"SD-1.

5. What is included in the Goniometer? Would we need to purchase items such as computers to run the Goniometer

The goniometer includes an industrial computer and touch-screen that control the gantry and stay on the machine always. It also includes a "working station" which is an off-the-shelf desktop with standard features. There are no extra hardware cards or drivers added to the desktop computer so it basically can be supported by any I.T. department.

6. What are the power requirements of your machine? Also, does the machine have a built in power supply for the fixtures?

The machine runs off standard 110VAC, approximately 5 amps maximum. We can supply an AC power supply that is computer-controlled with the system. It is a 1500VA, 15-1500Hz supply and can supply 16A up to 130VAC and 8A up to 240VAC.

7. About how long does the machine take to run a test on a lens? Additionally, can ware be tested on a machine prior to purchase?

The time of testing depends on the type of test being performed. "Production" tests that perform scans in the vertical and/or horizontal directions and individual testpoints typically take 1 - 3 minutes. A full "Beam Distribution", 0 to 360 left/right with 10 lines up/down, takes about 10 minutes. The higher the resolution of the cuts, the longer it takes. The system scans at approximately 15 degrees per second. We are an ISO/IEC-17025 Accredited Laboratory and Measurement house, so we can perform testing on products prior to purchasing the machine.

8. In the future, is it possible to add hardware to the machine such as faster motors or a more sensitive detector?

Currently, we do not believe there is a more sensitive detector in the market. Our system can resolve 0.001 cd at 100ft, and we have yet to see anyone else who can do that. Our motors already can move the machine much faster than would be safe and is recommended for photometric testing either. But yes, our system is upgradeable if new features do come along.

9. Does your machine include the following specs: MIL spec, FAA spec, and ICAO?

Our system allows the user to create functions for any type of movement and measurement that the machine is capable of, so you can create tests for whatever standard exists. If there comes a time that something is not covered, since we are the authors of the software, we can help to provide updates that accommodate unforeseen challenges.

10. Would it be possible to test both sides of a lens at the same time?

Yes, we can test both sides of the lens during the same "test procedure."

Hardware Questions

1. How many fixtures are programmed in the machine? Also, how difficult is it to change the fixture?

We only offer a sampling of the types of testing you would call "fixtures." We call them "Test Functions/Standards." However, it is extremely easy to enter in new functions as you grow your product line or testing needs.

2. How long would it take to obtain spare parts if the machine malfunctions? Any recommendations for spare parts that are readily available?

With a commitment from STS for our Photometric Maintenance Contract, we keep spare parts for each machine in stock. We have had the good fortune of having very few service calls; the few we had were linked back to poor power line conditioning at the customer’s site. We supply a battery-backup system with the machines, but nothing can really stop large voltage transients and continuous power outages from eventually damaging sensitive electronics. We don’t have anyone in the field who has required "spare parts" because we typically can supply them with what they need in 24 hours.

3. How are the goniometer motors controlled? For instance, are they controlled harmonically, stepper motors, or by indexing motors?

The motors are high-power stepper motors, controlled by high-power indexing drives.

4. How many variable axis adjustments are present on the machine?

The AP-48 has 3 axes of motion: Left/Right turning axis, Up/Down pitch axis, and linear fixture height adjust axis. All three are under automatic control with manual control at the user’s convenience.

5. What are the minimum angular intervals between measurements?

The resolution of the absolute rotary encoders we use is 0.01 degree increments of motion. Scanning resolution is 0.1 degree increments. It can be lower if you slow down the system.