SECTION 4 CALIBRATION OF ANALOG OUTPUT
In general, all flow measurement systems supplied by OMEGA
Engineering have been factory calibrated as specified by the
user, at the time of purchase.
Field calibration is only required when a change has occurred or
is sought to the measuring system. Such a change may be due to
repair, replacement or recalibration of the flowmeter, or perhaps
a change in the analog output span.
Begin by determining the equivalent maximum volumetric flow
rate in GPM, expected by the application, term this GPM
(MAX). GPM (MAX) may be calculated based on the analog
output scale requirements or may,be the maximum flow rate
listed on the flowmeter’s calibration sheet.
From the calibration constant (or K Factor) listed on the data
sheet for the flowmeter, obtain the frequency corresponding to
GPM (MAX) using Equation #1 and designate this frequency F
Equation #1 FMAX = KAVE X GPMMAX
The analog output of the FLSC-18B may be calibrated with the
aid of an external oscillator used in conjunction with a
The external oscillator is used to supply a test frequency. In this
method, the external oscillator is connected to the signal input
terminals as shown in Figure 4-1. The oscillator’s output
frequency is set to equal F (MAX) as indicated on the frequency
1. The course range adjustment is accomplished by selecting a
switch position on a DIP switch located on the PCA62 printed
circuit card. See Table 3-1 to determine required switch
position and set into switch as shown in Figure 3-2. for
anticipated F MAX.
It is necessary to open the cover of the enclosure by removing two screws
on side of box and lifting cover. Two printed circuit cards are attached. The
“RANGE” Dip Switch may be programmed with a pen. Input power should
be removed during this step.
2.. Connect a digital milliampmeter or digital voltmeter as
shown in Figure 4-1.