On-Board Scales?

It gets us pretty darned close. If there is a state scale we'll have to cross, we check (which would be advisable and in your best interest with ANY on-board system) it on a certified scale...but it isn't uncommon to load to +/- a couple hundred pounds of 80,000 on a pretty consistent basis. Once you know where on the gauge the needle is supposed to be for a legal load, you just put the needle right back in that same spot each time you have to load by the gauges.

Hell, even when I load on a scale and axle it out at the shipper, if it is close and I know there will be a state scale along the way, I'll still hit a 3rd party certified scale (i.e. CAT) to verify that the shipper's scale was accurate.

NO on-board system is going to be flawless. If your gauges tap into the air suspension for their readings, they are JUST as prone to error as by just using the gauges reading psi. Now if somebody has the money to spend on a system like that and are willing to do so, more power to 'em....just don't look for 'em in my trucks.

 

What the OP says about the gauges is correct. Even my digital one will change after moving. And I know how to use it. I can be at 55 PSI and think I'm a little over and then move and see it drop to 45 to get to the scale and be 31K on drives.

Worst part is that you have to let sit and allow air to build to get a good reading. When doing harvest work and corn or beans are being loaded they are not going to sit and wait to see what the weight is (even when I can find level ground).

So I think the reason that people like me do not want to spend the money on these is that we have seen over the years that at best it helps us get into a range but the need to scale is still needed.

With that said, I am thinking about getting gauges added to each axel on my spread. I don't think the people at Pilot/TA/etc could figure out how to scale a spread to save their lives.

 

So what does your system rely upon if not on the air pressure in the suspension?

Air pressure will vary depending upon the square inches of surface area in the bags (does not change with weather/elevation) and the mechanical advantage the bags may have based upon their location relative to that of the load center and the pivot point...leverage (which does not change with weather/elevation) in relation to the weight of the load placed upon the suspension (which does not change with weather/elevation). When you put a load on an axle group, it takes an equal & opposite force to hold that load up. The basic laws of physics aren't going to change with the weather or with elevation.

Sure, uneven terrain can cause issues, because one axle in the axle group is supporting more weight than the other. Depending upon which axle it is carrying more than it's share of the weight, the scale could read high or low. So, you move the truck a little to see what the gauges do....try to find level ground to load on.

How is your system going to be different?

 

I'm willing to bet that if your company is willing to put their money where their mouth is by paying the cost of tickets and fines if they use your product properly and still come up illegal - you MIGHT make a few sales.

Back up your claims with a guarantee.

 

Please post a link to your system or pm me your email I would be interested in looking into your system

 

Githiun, I'm against the Elogs, but the more the government tightens up on HOS and forces Elogs on us, the more demand there will be for your product.

Here's why:

Take driver A. He is on paper logs, or working for a company that is loose on the log audits. He loads at a shipper, and scales three miles away. Sure enough, he's heavy so he needs to come back and rework the load. That driver may just not log the couple hours that this takes. He donated his time, but at least it didn't eat up his available driving time because he just didn't log it.

Now look at driver B. He is on Elogs or has an aggressive log compliance officer. He will HAVE to log it, and he just lost two hours off his eleven. THAT is the guy who will spend money on your system and it will pay itself back the first couple times he doesn't have to return to rework the load.

The tighter they get on HOS, the less we can afford time wasted going out of route to scale, or rework the load when its later discovered to be heavy.

 

You were told wrong.

Yes, air expands as it gets hot, and contracts as it cools off...and if the suspension system were a closed system, that MIGHT have an effect on the pressure. However, it is NOT a closed system, and the pressure inside the bags does not change with temperature.

As the air expands and contracts with the temperature change, the leveling valve allows air to enter or exit the suspension's airbags as needed in order to maintain the ride height at the preset level.

The weight of the load has not changed. The surface area of the airbags has not changed. The airbags relative position to the axle and pivot point has not changed. In other words, it is still going to take the same amount of pressure per square inch in the airbags to support the load, whether it is 10 degrees outside or 100.

That pressure is what the air gauge is measuring.

In other words, your sensors are programmed to convert air pressure to a corresponding weight, taking into account a few extra variables which have zero effect upon the air pressure reading...

...and a person who's eyes hurt when trying to understand a complex equation is trying to give a math lesson to a person who could probably do the math in his head....

I've never had any issues or headaches when using simple air gauges. Once you are familiar with where they need to be when loaded to the max legal load, you can get pretty darned close each and every time you load. If you have to cross a state scale while loaded, it is in your best interest to verify your weight at a certified scale before you hit that state scale anyway....whether you loaded on a shipper's scale or based off ANY on board system. Both do a great job getting you CLOSE...but there is no guarantee to be 100% accurate.

 

3,000 lbs> try 300 pounds

Does you system work on uneven ground?

What's your guarantee?