Measure 600V and 10A with 24 bit resolution through 50 meters of space and 6 months of time
The Mooshimeter makes multi-channel measurements possible in situations that are too fast, too slow, too sensitive or too dangerous to use a traditional multimeter. By harnessing your smartphone’s hardware through Bluetooth 4.0, it does so at an insanely low price.
Where did it come from?
The Mooshimeter was born out of our frustrations as electrical engineers at the limitations of the “standard” digital multimeter.
Almost every digital multimeter will only let you use one mode at a time, meaning that to watch relationships in an active system you need to use multiple meters. Most have a front panel dominated by a numeric LCD display and a gigantic mode selection knob. Having the display mounted on the measurement hardware makes it very difficult to measure moving or enclosed systems, because the user must have clear line of sight to the meter to be able to read it.
Over the last few years, many of us have started carrying big beautiful touchscreen radios in our pockets all the time. The Mooshimeter uses the hardware you’re already carrying with you to provide features previously available only on much more expensive instruments in a tiny, durable and affordable package.
A wired meter forces you to get up close and personal with what you are measuring. This can be a mild inconvenience or downright dangerous. The wireless link provides you the freedom in your measurement to:
• Allow a Mooshimeter to be on the wrong side of a blast shield while you exercise the better part of valor.
• Make measurements across water- or air-tight seals.
• Measure performance without having to chase after your robot.
Monitor even the feistiest robot in real time!
• Finally answer the question we’ve all had since we were 4 – Does the light in the refrigerator actually turn off when I shut the door?
Read ambient light with a photoresistor and ambient temperature
SPOILER ALERT – yes
Why Simultaneous Sampling?
One channel means you can monitor a state. Two channels means you can monitor a relationship.
Most meters can only measure one thing at a time. The Mooshimeter can measure any two of its 3 inputs.
The high-speed synchronized measurements allow for very fine measurement of power, including:
- Actual power usage: Measuring Volts and Amps on separate meters and then multiplying gives Volt Amps, which is Watts only when the Power Factor is perfect.
- Power Factor: How effectively are you using the power provided?
- Harmonic Distortion: What sort of noise is being pushed back on to the lines?
Simultaneous voltage and current also lets you see more detail on how your system performs across its operational range.
- Measure the performance of a battery under actual load conditions.
- A battery’s impedance is a much better indicator of its health and state of charge than voltage alone.
- Measure speed and torque of a brushed DC motor without modifying the existing circuitry.
Capture the IV curve of a car battery by cycling the fan setting
Why 24-bit Resolution?
In the world of DMM’s, precision is usually given as a number of digits. The cheapest meters are usually 3.5 digits and carry a 12-bit ADC at their core. An entry level professional meter will usually be 4.5 digits and have a 16-bit ADC internally. The Mooshimeter reinvested the money saved by dropping the display and interface hardware back into the measurement components and is built around a 24-bit ADC. This gives you up to 7 digits to work with, though for most measurements expect 5-6 noise free digits. Combined with the graphing capability of your smartphone, this allows you to pick up the smallest and most subtle signals.
• Measure heartbeats like an EKG
• Pick up the output of an unamplified strain gauge across its entire range
5uV/div vertical scale on the display
• Measure from -10A to 10A in 2uA steps
Most multimeters add 1-10 millivolts / milliamp of burden voltage when measuring small currents! This drop can easily be enough to kick a USB device off bus or brown out a microcontroller.
The Mooshimeter’s current measurement mode introduces 20 microvolt/milliamp of burden voltage when measuring in 2uA steps over a full 10A range. Capture the sleep currents and the active currents of your digital circuits without autoranging.
And last but definitely not least, extreme voltage resolution allows you to…
• Measure arbitrarily large currents without rewiring
The Mooshimeter’s voltage resolution allows you to use the burden voltages already introduced by your system’s wiring to measure currents without disconnecting anything! Perfect for delicate digital systems and large power systems alike.
• Measure hundreds of amps with two alligator clips and a zip-tie.
The Mooshimeter accepts a microSD card up to 32GB and can log data for months. Just set up the sample rate through the app and walk away. The data is timestamped and saved either in binary or CSV. Life is short, you don’t have 12 hours to watch your battery charge.
Impatient engineering types just want to skip the song and dance and go right for the numbers. Here they are, and here are some keywords for all you CTRL-F’rs: spec sheet, specification sheet, data sheet.