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Ultrapure nitrogen gas (Pyxis DCC-3 P/N 42059) is recommend for the zero calibration. The slope calibration
requires 0.02% to 0.1% (or 200 to 1000 ppm) oxygen in nitrogen gas (Pyxis DCC-4 P/N 42060). The user can
connect the gas source to the gas inlet port. Portable standard calibration gas cylinders can be purchased
from Pyxis if desired.
*NOTE*
Pyxis does not provide the C-10 regulating valve for gas cylinders.
For low pressure applications users may also conduct ZERO calibration of the ST-774 sensor with 5% cobalt
catalyzed sodium sulfite solution.
As an alternative and far faster/easier option, Pyxis Lab offers
ST-774 SERVICE SWAP
(P/N ST-774 SWAP).
This service provides the user with a new or reconditioned ST-774 sensor calibrated and ready for service
in exchange for the unit in need for calibration/service removed from the system. Contact Pyxis Lab for
details at
UC-50 Operation
5.1.
Main Screen
The UC-50 is configuraed to read and display measurement data from the Pyxis ST-774 dissolved oxygen
probe. The system time, ST-774 DO ppb reading and the sample temperature measured by the ST-774 are
displayed on the main screen. The green dot on the upper right of the screen indicates normal
communication between the UC-50 and the ST-774 probe. In the bottom of the screen, the analog input
(AI) value, the analog output (AO) value, and the relay status are shown.
Figure 5. Main Screen
