Campbell Scientific CR800 and CR850 Measurement and Control Systems - Manual (Page 447)

Section 11. Glossary
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UPS
Uninterrubtable power supply. A UPS can be constructed for most
datalogger applications using ac line power, an ac/ac or ac/dc wall
adapter, a charge controller, and a rechargeable battery.
User Program
The CRBasic program written by the CR800 user in the CRBasic Editor or
the Short Cut program generator.
USR:
A portion of CR800 memory dedicated to the storage of image or other
files.
URI
uniform resource identifier
URL
uniform resource locater
variable
A packet of CR800 memory given an alphanumeric name, which holds a
potentially changing number or string.
Vac
Volts alternating current. Also VAC. Mains or grid power is high‐level
Vac, usually 110 Vac or 220 Vac at a fixed frequency of 50 Hz or 60 Hz.
High‐level Vac is used as a primary power source for Campbell Scientific
power supplies. Do not connect high‐level Vac directly to the CR800.
The CR800 measures varying frequencies of low‐level Vac in the range
of ±20 Vac.
Vdc
Volts direct current. Also VDC. The CR800 operates with a nominal 12‐
Vdc power supply. It can supply nominal 12 Vdc, regulated 5 Vdc, and
variable excitation in the ±2.5 Vdc range. It measures analog voltage in
the ±5.0‐Vdc range and pulse voltage in the ±20‐Vdc range.
Volt meter
An inexpensive and readily available device useful in troubleshooting
data acquisition system faults.