Stand alone voltage/etc monitoring?

  How can I best monitor power quality (ie: voltage, etc) as a colo
customer? We monitor temperature and humidity in multiple places on each
floor we are on, network bandwidth/errors/latency/pps/link-state on
every link, power used per circuit, tons of metrics on servers, but I
can't seem to find a simple and small way to monitor voltage, etc. I
looked in the routers, cabinet-level switched power-strips (CDUs),
switches, and servers, and I don't see anything we already have that can
report that info. I see there are probably some small UPSes ($400 or so)
that can report this info. Seems silly to buy UPSes to get that info.

  Is there a quick/small/handy/better way to get power quality info? If
so, what is it? I don't own the facility.


I've looked at various inline power monitoring appliances solutions and
honestly, most of them will cost more than a small UPS. The question
is, where do you want to monitor the voltage? At the input side of the
rack-PDU? Are your PDUs manageable? Do you want to monitor voltage to
each device (output side of the PDU)?

Or do you just want to sample monitor on the side (as opposed to inline)
and fed from the same circuit feeding the input side of your PDUs
assuming all your equipment/PDUs are receiving the same power quality?
I monitor at the UPS for my home systems. My UPSes are APC brand. A
SmartUPS 500 w/Web/SNMP card will run you about $350 to $400 and you
poll them for input voltage and frequency. Here's a snapshot from a
couple of years ago... I do have dirty power.

The modern digital utility meters have extensive monitoring for power quality. We have been using meters from EDMI[1] that can report and record voltage, current, power factor, voltage and current waveforms, harmonics, demand profiles and many other things.

The meters have serial interfaces and are fairly easy to connect up for remote access.