Ronan X96S DENSITY GAGE - Manual (Page 51)

Density Gage Manual 012407 47
High Calibration (Dual Point Calibration)
An alternate calibration technique is the "Dual Point Calibration" where samples of TWO different process densities (d o1 and
d o2 ) are drawn, analyzed, and entered into X96S software.
With the addition of a second known density (d o2 ) the X96S software can now compute very accurately the value of 1/ut, which it
uses to determine the process density.
The calibration procedure also reverses the relationship between detector counts and actual process density. Now, a direct
relationship exists, so that as the process density changes from light to heavy, the X96S's display screen indicates an increase in
user units from minimum to maximum - (example: 1.1 SpG to 1.25 SpG.)
The transmitter output signal also increases from minimum to maximum - (usually 4 to 20 mA).
The exponential algorithm used by the X96S software ensures an accurate measurement and eliminates the need for linearization
through a separate stage of signal processing.
Preparation for Calibration
WHAT type of process sample is needed?
Any conveniently obtained process density that is within the range of interest can be used. For example, water-based slurries could
use water as the reference sample. Sub-water slurries could use an empty pipe for the reference condition.
WHAT type of sampling procedure is needed?
The sampling procedure will depend upon your own process. You will have to do what is necessary to obtain a truly representative
sample of the density(ies) on which you are calibrating. Pull a minimum of three samples of each density. (This means at least
three samples of one density for single-point calibration, and at least three samples of two densities for dual-point calibration).
Take necessary precautions to preserve the integrity of each sample.
WHAT type of laboratory analysis is required?
Precise laboratory analysis will produce the most accurate and useful results. If the results are temperature compensated, you will
need to enter the uncompensated values(s) into the X96S software.
Final gage measurements can be only as accurate as your sampling and analysis technique and level of accuracy.
EQUIPMENT SHOULD BE RUNNING AT NORMAL ENVIRONMENTAL CONDITIONS - TEMPERATURE, PRESSURE,
PROCESS FLOW, ETC.
Dual-Point Calibration Procedure
The dual-point calibration uses two separate modules in the X96S software. First you will REFERENCE the system at some
known low density, and then you will CALIBRATE the system at some higher density.
The second part of the dual-point calibration will permit your system to calculate a "calibration constant" (1/uT) for your process.
This can be done through the CALIBRATION module sequence, which is located in the customer-programmable functions.