I am in the medical profession and this has been the most accurate BP machine I have had for almost 18 years. The self pump models stay more accurate than auto inflate in my opinion. I calibrate mine at work with a mercury machine and its rarely off more than 2 points. Remember you should take 3 readings at one point in time , one minute apart, and average them for the best result. Can't find a better machine than this. Must not bang around!
It depends on the seller who is selling it. We try to be the lowest seller on Amazon but there are many sellers selling this same product. Depending on how competitive the other sellers are, will affect the pricing change differences.
The most common error symbol that appears on the display panel is a EE with a down arrow and two numerals. The reason for the EE Error Indicator is generally caused because the cuff has been wrapped too loose. The cuff was under-inflated during the measurement. This error will also display if the cuff is worn and needs to be replaced. The EE symbol with a down arrow indicates the cuff is over-inflated. In most instances the cuff has been wrapped too tight or you are using the incorrect cuff size. Turn the monitor off. Read the instructions to correctly apply the cuff. Wait five to ten minutes then take another measurement. Error indicators vary by model number. Symbols that display on your model are printed in the instruction manual with the steps to correct the problem. P.S. It's not my own info, got of the internet, but that makes sense:)