I bought a really cheap (£5/$10) multimeter ages ago. It mainly gets used for testing mains, but I've started using it for electronics. I had to replace the fuse recently (250mA quick blow).
I was playing today with a few Microchip voltage references and a temperature sensor. At first, the meter showed a small negative DC voltage without probes. The output of my 7805 circuit showed around 4.8v and an MCP1541 showed under 4v.
After a while the readings 'corrected', 7805 showed 4.96v and the voltage reference 4.06v. What causes these readings and the correction? The battery should be fairly new and isn't rechargable.
I don't really have much money to spend on a new one, but what should I look for if I buy one? Do I need one, or should a cheap one suffice? I don't mind too much about autoranging, but something accurate enough for this use would be nice!
Interestingly, the one I have appears on the EU "unsafe goods" list (Mastech M-830B). That can't be very good![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
EUROPA - Consumer Affairs - Unsafe products
I was playing today with a few Microchip voltage references and a temperature sensor. At first, the meter showed a small negative DC voltage without probes. The output of my 7805 circuit showed around 4.8v and an MCP1541 showed under 4v.
After a while the readings 'corrected', 7805 showed 4.96v and the voltage reference 4.06v. What causes these readings and the correction? The battery should be fairly new and isn't rechargable.
I don't really have much money to spend on a new one, but what should I look for if I buy one? Do I need one, or should a cheap one suffice? I don't mind too much about autoranging, but something accurate enough for this use would be nice!
Interestingly, the one I have appears on the EU "unsafe goods" list (Mastech M-830B). That can't be very good
EUROPA - Consumer Affairs - Unsafe products