It’s #sensorsunday and this weekend I finally got to use my DIY thermal chamber 😃
Along with a Fluke thermocouple meter it turned out really good 👍🏼

Doing temperature test on the 1M #vintage reference resistor - it’s big and heavy, so I left it to soak at the wanted temperature for at least 8hrs, continuously monitoring chamber and device temperature.

Testing at 10,20 and 40C, I found a slightly negative temperature coefficient, but still well inside the 0.02% specification.

My measurements are a bit lower altogether compared with my initial test where I saw precisely 1M. This is due to coupling between the test wires, when entering the thermal chamber. It’s really hard to avoid, even giga-ohms in parallel, will affect the result.

#testandmeasurement #electronics #metrology #electronicsengineering #engineer #fluke #sourcemeasureunit #keithley #keithleyinstruments

@whitequark
Thanks for the recommendation! Got it to work with sigrok and can use it as a limited #SourceMeasureUnit / #CurveTracer while working on my own design (which can take ages to finish). Will still need a multimeter to pair it with; the LEDs I measured start lighting up way before the minimum current the RD6012P could measure (display said 100μA, multimeter read > 300μA which is well within spec).
1/2

I received some, likely counterfeit, REF200 chips - a quick test with my #keithtley #sourcemeasureunit proved them quite accurate though, so I decided to repeat a classic experiment from early university days: charging a capacitor with a constant current source.

We’re all used to that exponential rise seen in a RC circuit, but replacing the resistor with a constant current source, we get a beautiful linear ramp instead, it’s incline solely determined by the current and the capacitor values.

I knew upgrading to a 4CH #oscilloscope was a good idea ☝🏻😂

#electronics #electronicsengineering #physics #basicelectronics #engineer #hamr #hamradio #mylab #testandmeasurement

Testing my 1988 #burrbrown REF200 - this is likely the first time it sees power since it left the factory 🥹 My #eevblog multimeter and my #keithley #sourcemeasureunit agree: 100uA well within the 0.5%.
The metal can TO-99 housing has a special feat though: it’s specified from -55 to 125C, amazing 😃

#electronics #engineer #electronicsengineering #testansmeasurement