If the places that were shorting you have to raise prices when they have to give you what you paid for, that's false economy -- you're not saving money, if you want to drink less beer to save money, ask for a smaller glass.
Anyone who has spent even a short amount of time in the food service business will be familiar with shrink. The average bar is probably seeing more than 15% shrinkage. The short pours are probably not offsetting that loss. Margins are thin.
Solutions for the neurotic drinker this website appeals to: - order a can or bottle - buy retail and stay home - go to a self pour joint and pay by volume. Bonus: you don't have to talk to anyone.
Otherwise put away the scale and talk to the bartender. Chances are you come away with plenty of free beer. Most small taprooms will help you find a beer you like by giving you free beer. If you're obsessing over getting what you paid for in food service, you're missing out on the true value of that industry.
Let's not harass our bartenders, a hell of a tough job, with scales. I spent years behind the case of a cut to order cheese shop. There's a time and place for scales. This is not it.
If you go to a beer bar or a tap room, a large part of the role of a bartender is helping you find beer that you like. Successful bars and bartenders thrive from repeat customers. Community is important. This is very obvious if you actually sit down at bars and talk to the people behind them.
People need to know how much they got. it can be hard to judge, especially as you will be comparing across visits to different places on different days, and different styles of glass, etc.