Load cell questions

Help & Support Robot Parts
1

Hello,

I’m developing a soil probe that will have your load cell mounted to it (so far I’ve been using a .78kg load cell). I have some questions:

  1. do you sell a 1kg load cell? i can find it elsewhere but i’d rather deal with you guys because of the support you provide
  2. what exactly is creep? does it mean that if a force of 780g is placed on the load cell for a long period of time (say a week) that the voltage output will become innacurate?

thanks,
jesse

2

Hi Jesse,

]For the moment, we unfortunately don’t have the 1Kg Load Cells in our catalog./:m]
]You are correct, the creep is the change in a load cell occurring with time under a near capacity load and with all environnemental conditions being constant. It’s usually expressed in units of % of the applied load over a specified time interval (hours or minutes)./:m]Regards,

3

Thank you for your reply. I would like to follow up on question #2

Suppose i have a load of 780 grams (full load) on a cell for a period of 500 hours (3 weeks). the creep is 0.1%F.S/30min., and i’m applying 5v to the strain gauge, so I’m getting around a 4v signal initially. does this mean that after 500 hours (1,000 x .1 = 100), my 4v reading will now be 100% innacurate?

that’s part a

part b is: suppose i then take the 780 g load off the cell completely, so it reads 0 v. Does the cell “bounce back” so to speak, or start working again? or is it permanently damaged? another way to say this is…does the cell “refresh” its accuracy once the load is taken off?

thank you

4

Hi,

]The creep percentage of the load cell won’t be the same over time. It will decrease gradually with time. In other words, let’s say for instance for the first 4 hours, , the creep is 0.1%FS per 30 minutes, then this percentage will decrease for another interval of time until it reaches 0% before passing the 3 weeks. Therefore, the output signal will reach an asymptotic value and won’t change, this value could be, for example, 20%FS./:m]
]There is the creep and there is also the creep recovery which is the "change in no-load output occurring with time after removal of A load which had been applied for a specific period of time. Usually measured over a specific time period immediately following removal of rated load and expressed as a percent of rated output over a specific period of time. " Normally, the applied interval and the recovery interval are almost equal (Please take a look at the attached picture)./:m]Cheers,
loadcellcreep.png