Environmentally Hardened Rugged Terminals
At Beijer Electronics, we use extensive environmental testing to ensure our line of QSI terminals meet various standards, and to guarantee highly-reliable operation of our products. We use three main phases of testing to ensure the quality of our products: qualification testing, acceptance testing and sustaining testing.
Qualification testing is done during the development of a new product. It is very exhaustive and often terminals are tested to destruction. Acceptance testing is ongoing testing done after a terminal enters production. All QSI brand terminals receive some level of acceptance testing, depending on the specifications, intended application, and occasional customer requirements. Sustaining testing is more extensive than acceptance testing, and is performed on randomly selected production terminals, to ensure our finished products remain entirely compliant with their specifications.
Our test processes are derived from many of the published standards which state environmental test conditions, such as MIL-STD-810 (test protocols), MIL-STD-202 (test limits), and SAE J1455 (for equipment intended for use in vehicles).
Our Environmental Testing Includes
- Operating / Storage Temperature
- Thermal Shock
- Sealing (e.g., NEMA 4, IP 67)
- Operating / Storage Vibration
- Physical Shock
- Physical Drop
- Electrostatic Discharge (ESD)
- Wind-blown Rain & Dust
- Power Line Transients
- Electromagnetic Interference / Compliance (EMI / EMC)
- Key Durability
- Acceptance Burn-in
Operating / Storage Temperature
We use several different environmental chambers, all with dual-stage refrigeration (-73 to 190 °C range), to test all our designs to the rated operating and storage temperature ranges. A typical qualification test for operating temperature will be a 24-hour test, with the temperature cycled between the high and low limits on a four-hour cycle, while power is being applied. The UUT will be connected to an external computer that controls power and monitors the UUT for proper operation and logs any failures.
Storage temperature testing is similar except the unit is not powered during the thermal cycling, the test is 48 hours long and is tested for proper function at the end of the test period.
Humidity testing is performed at the qualification stage on all terminal designs. This is typically a five day test, with the UUT soaking at the rated temperature and humidity for the entire period, while an external computer periodically cycles power and monitors the UUT for proper function.
Thermal Shock testing is performed at the qualification stage on terminal designs which have this specification. The testing is done utilizing two environmental chambers, one at the high temperature and one at the low temperature. The chambers are close to each other, allowing a UUT to be soaked in one chamber while connected to a monitoring computer, and to be moved in a few seconds to the other chamber. This subjects the unit to a very rapid cold-to-hot, or hot-to-cold, thermal shock. The computer continuously monitors the unit for proper operation.
There are a variety of sealing specifications, such as NEMA 4/12/13, IP67, SAE J1455. Depending on the specification for a terminal design, we may test it with our in-house spray chamber or send it to an independent laboratory. For example, our in-house spray chamber is suitable for J1455 and NEMA 12 testing, but the tremendous water volumes required for NEMA 4 testing require that we send the units to a laboratory properly equipped to test and certify this sealing.
Operating / Storage Vibration
All QSI terminal designs undergo some level of vibration testing, using our 2.6 kN Unholtz-Dickie shake system. This computer-controlled shaker allows us to do a variety of testing, such as sinusoidal sweep, random, and PSD. A typical test will be two hours of vibration to specified levels on each of three axis. For operating specifications, the unit is powered and monitored during the vibration. For storage specifications, the unit is not powered, but is tested for proper function at the end of the test period.
Our same Unholtz-Dickie shake system can do programmed shock testing. Shock testing generally takes far more time to set up than to perform, as the shocks themselves are less than a second long.
Some units include a "drop" specification, such as "can withstand two meter drop onto concrete." Beijer Electronics engineers test their interim designs using a ladder and a concrete floor, then final designs are tested at an independent laboratory using a "drop tester," which is a machine specifically designed to drop the UUT without any rotational motion, to ensure the most rigorous impact. View the QTERM®-G55 drop test video.
Electrostatic Discharge (ESD)
All QSI brand terminals are tested for resistance to ESD, using our in-house 16 kV test equipment. Since Beijer Electronics makes products that are touched by ungrounded personnel in normal use, this is a particularly critical requirement.
For units requiring dust resistance (typical in heavy construction vehicles), Beijer Electronics uses an in-house dust chamber, compliant with J1455 requirements, to do dust testing. Because the "dust" used in testing is fine Portland cement, which is nearly impossible to entirely clean from a unit, this is considered a destructive test, even when the UUT successfully completes the test.
Wind-blown Rain & Dust
Again typical of heavy vehicles, some terminals have wind-blown rain and dust specifications (see MIL-STD-810). Beijer Electronics has a wind tunnel specifically designed for this type of testing, and we can do testing with wind speeds of up to 90 km/h.
Power Line Transients
All QSI terminals must meet some level of resistance to power line transients. Vehicle terminals in particular are subjected to very "dirty" power inputs (e.g., load dumps, reverse polarities, positive and negative spikes), and must have power supplies that can operate properly under these conditions. Most of the testing for power-line transient immunity is done using in-house equipment, and, where a specification requires it, we have final designs tested and certified by independent laboratories. Our experience has shown that J1455 is not adequately rigorous in some areas, and merely being compliant is not adequate. Therefore, Beijer Electronics vehicle terminals exceed J1455 requirements for power line immunity where necessary.
Electromagnetic Interference / Compliance (EMI / EMC)
There are both mandatory (FCC Part 15) and voluntary EMI/EMC standards with which various Beijer Electronics products comply. While we do most of this testing using in-house equipment, where a product is specified to comply with a mandatory EMI or EMC standard, that product has been tested and certified to be in compliance by an independent laboratory.
All QSI keypad designs are rated to two million actuations. All designs are tested using our in-house test fixture. This fixture uses compressed air and an electronic valve to repeatedly press the key, while a computer monitors key bounce (up and down) and key resistance (open and closed). These parameters are logged and provide a clear picture of key durability. A typical two-million-cycle test will take about eight days at roughly three key presses per second.
All QSI products receive some level of environmental burn in. At a minimum, all PCB assemblies are cycled from -40 to 85 °C for 22 hours, to induce thermal stress and force failures of any bad solder joints. Higher-end terminals (particularly those used in vehicle applications) are given this same burn-in after assembly and while operational; the units are monitored during this testing.
If you would like more information about our environmentally hardened terminals please email our sales department or call us at 1-866-OITERMS (1-866-648-3767).