In-Situ Calibration Check
All Sage Thermal Mass Flow Meters feature the ability for the customer to verify the meter's accuracy, as long as a "No Flow" (0 SCFM) condition can be created.** With the Insertion Style Flow Meter, and an SVA05 Isolation Valve Assembly mounting accessory, creating a "No Flow" condition is easy, and takes only a few minutes. See graphic to the right (3-Easy Steps: Loosen, Lift, and Look). More importantly, this simple 3-step procedure can be done In-Situ (i.e., at the site).
The ability to provide a convenient In-Situ calibration check is unique to Sage, and it is a direct result of having developed a digital method of driving the sensors (versus the traditional drift-prone Wheatstone bridge). Since the Sage Flow Meter has extraordinary reproducibility, even at a "No Flow" (0 SCFM) condition, it is an easy matter for the customer to validate that this unique data point hasn't changed since the original NIST Traceable calibration (see Zeroing Chamber photo, below). Simply compare the observed milliwatts (mw) to the Factory's original data point (noted on the Flow Meter's Certificate of Conformance or the meter's Tag). In fact, since the Flow Meter's raw calibration data is linearized with a 5th order Polynomial, that is stored digitally, any reproducible data point is sufficient to verify that the original data is intact, but only a "No Flow" (0 SCFM) data point can be truly generated by a customer in the field.
This proprietary technology provides additional benefits as well: Enhanced signal stability; improved temperature compensation; greater sensitivity to flow changes; improved resolution; and even the ability to digitally adjust the dynamic operating range of the meter for the specific process conditions the customer has specified.
The unique Sage In-Situ calibration check assures that the Flow Meter still retains the original NIST Traceable Calibration, and in addition to verifying the meter's accuracy, also confirms that the sensors are clean, and that the Flow Meter hasn't drifted or shifted. This is a tremendous benefit to our customers, since it eliminates the cost and inconvenience of annual calibrations on the flow meters.
Please refer to page 46 of the Sage Prime Operations and Instruction Manual for further information, or refer to the equivalent In-Situ Calibration Procedure in any other Sage product's Operations and Instruction Manual.
SAGE ZEROING CHAMBER One of the many data points taken during the Flow Meter's NIST calibration at Sage is at a "No Flow" (0 SCFM) condition. The Sage Zeroing Chamber is used to capture a "No Flow" (0 SCFM) flow point at the actual conditions (i.e., with the same gas or gas mix and same pressure as that specified by the customer for their process)