The system takes one to two minutes per tire to install and the sensors read 24/7, whether the vehicle is moving or parked. “Many systems only give you pressure readings once you’re moving at about 15 to 20 miles per hour, although by that time, you’ve already left your yard so you’re on the road and have to turn back around,” Zaroor says.
She continues, “We can give people and fleets the continuous tire pressure monitoring any way they want it.” That includes hooking it up to a telematic system or integrating it into a current telematic system. She also says they’ve worked with GPS companies to integrate their technology directly into that monitor so there doesn’t have to be a PressurePro monitor in the cab, as there are already so many viewables in the cab already. Zaroor adds, “It’s hard to break it down, to simplify it, because we do it so many different ways.”
Another system that attaches to the valve stem and monitors the pressure continuously is Fleet Specialties’ Tire Sentry Systems. Bill Shore, operations manager - tire pressure monitoring systems with Fleet Specialties, explains that the tire pressures can also be read by a handheld system in the yard. “That system is ideal for vehicles or fleets that come to the yard at the end of the day or where they’re doing a fueling station. They can be checked before they go out or when they come back.”
The handheld device can be pointed at a vehicle to get a pressure reading to detect any low tires. He says, “There are also the onboard systems where it will monitor tires from a panel. The most economical system for a bus fleet, however, would be the Yard Sentry handheld unit. All they would have to do is equip all the tires with the sensors and just have a signal yard monitor.”
The 360 HD is the monitoring system offered by Doran. It also has basically an over-sized valve stem valve cap that screws on the end of the valve stem and transmits the pressure reading through an FM radio signal. Chris Nau, Tire Pressure Systems – Truck, with Doran, says, “Our approach is to have the dash monitor display provide information to the driver with a limited number of moving parts.” He adds, “By keeping it all electronic, it really simplifies the long-term, wear-and-tear aspect of it.”
He also explains that it is an epoxy-like material that houses the internal components of the sensor. “If you were to look at our sensor, the first component that you would see in a profile view is a circuit board, a battery and another circuit board that has an antenna on it. That material fills up that sensor all the way up to that transmitting antenna. By doing that we’re going to minimize any potential damage that could result from vibration, impact and the environment.”
The system has a fast-leak warning and a low-pressure warning. If any pressure drops 2.8 psi within 12 seconds, the operator gets a fast-leak warning and they know they are in a critical situation and can react accordingly.
A system that works without anything on the vehicle is Ventech’s Pneuscan, which consists of a sensor on the ground that vehicles drive over to get pressure readings and tread level readings. Krause of Ventech explains, “There is nothing installed on the vehicle, no modification to the vehicle. The sensor plate is embedded into the ground of the transit authority, in a place that’s highly traveled; tire pressure is measured daily or sometimes more than daily.”
“The physical basics are quite easy,” says Pingel. “The pressure that the tire brings to the street is depending on the pressure inside. That means if you have more pressure inside, the surface — the footprint — gets smaller. If you put more load on the tire, than you have a larger footprint.” In other words, the inner pressure transfers down to the outer pressure and what it measures with the sensor is the pressure distribution outside of the tire on the ground and calculates on that, the tire pressures.
Pingel emphasizes, “You can take any vehicle, drive over the sensor and the sensor measures the pressure. We don’t need to know what tire it is, what size of tire it is, the measurement is independent of the tire.”