Showstoppers
Some of the other DMMs on the market have severe flaws that won't show up on the specs. Look out for DMM front ends that emit high energy spikes, unstable inputs, high burden voltages, voltage spikes and high test voltages. Look out for DMMs with massive software installation packages.
| High Energy Spikes |
| Its important for a DMM to be a passive device. Unfortunately, this is not always the case. Some competitors DMMs periodically emit 800 mV spikes, even when measuring 100 mV! |
| Unstable Front Ends |
| Some of the competitors DMMs have front ends with a high offset drift and low input impedence. This has negative effects on accuracy. Turning on Autozero to correct for this issue results in slow measurement rates, and can cause voltage spikes (see above). |
| High Test Voltages |
| Signametrics uses industry standard Test Voltages for making resistance measurements (3 V). Some other companies use test voltages over 10 volts. This may work fine for measuring resistance on a calibrator, but is not useful for measurements on real world circuits. Sensitive circuits could be damaged, and semiconductors could turn on. |
| High Burden Voltages |
| For measuring DC & AC Current, Signametrics DMMs provide burden Voltages around 0.12 V at 1A, which are standard in the industry. Some competitors have over eight times as much Burden Voltage. This severely interferes with the Device Under Test. |
| Software |
| Some DMM software installations take up over 1GB of hard drive space,
and add several startup programs to Windows. Signametrics installation
is under 10MB, with no programs slowing down your system startup.
Another issue is companies that use their DMMs as a vehicle to sell you their software. When you upgrade a one piece of hardware or software in your system, you may be locked into purchasing additional software updates that you don't want or need. |
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