Seametrics TX800-Series - Manual (Page 8)

OPERATION
Page 6
Calibration (“K-factor”). The K-factor represents the ac-
tual number of pulses per gallon the meter produces during
a flow test. This number can be entered into your electronic
control to make it read properly. If the TX800-Series meter
is ordered with a tee fitting, it is factory-calibrated in the
fitting and the K-factor is indicated on the side of the fit-
ting. For saddle and weldolet K-factors, see the K-factor
calculator located at the bottom of the www.seametrics.
com home page.
10031295
MF81T-P200
K: 53.6
Find Your K-Factor Here
1½" 2" 3" 4" 6" 8"
Min 1.1 2.1 4.6 7.9 18 31
Max 190 314 691 1190 2700 4680
Flow Range (Gallons per Minute)
1½" 2" 3" 4" 6" 8"
Min 4.16 7.95 17.41 29.90 68.14 117.35
Max 719.23 1188.62 2615.72 4504.64 10220.61 17715.73
Flow Range (Liters per Minute)
Modularity. Any of the TX800-Series flow sensors can
have electronic modules mounted directly to them, either
at the time of order or by adding an adaptor kit in the field
(part number 102632). Alternatively, the flow sensor and
indicator or transmitter can be installed remote from each
other. The FT420 is an indicating transmitter (rate, total,
4-20 mA output), and the AO55 is a blind 4-20 mA trans-
mitter. For data logging, add the DL76. The FT520, which
provides batching and other functions, is suitable for re-
mote installation.
Output . The output is a current-sinking pulse (square
wave) compatible with many controls in addition to the
Seametrics indicators and transmitters. The most com-
mon of these are water treatment controllers and pro-
grammable logic controllers (PLC’s). For these units, it is
sometimes necessary to provide a pull-up resistor if the
controller does not provide for a current-sinking output.
(See the section on “Connecting to PLC’s and other con-
trollers” before connecting to a non-Seametrics control.)
Fittings. Since the TX800-Series sensors are not adjust-
able, they must be purchased with fittings appropriate to
the application. The TX810 is sized for fittings of 1 1/2” to
3”. The TX820 is for fittings of 4” and 8”. Each fitting in-
sures that the flow sensor is installed at the correct point.
Every flow sensor and every tee fitting is wet calibrated.
Saddle fittings are normally not wet calibrated, because
they are field-installed on a pipe. In PVC however it is pos-
sible to order a saddle pre-installed on a standard length
of pipe, in which case the entire assembly is wet-calibrat-
ed. For all other saddles, the K-factor (pulses per gallon) is
established through testing with various standard sched-
ules of pipe and provided with the saddle.
Minimum Flow. As with any other flow sensor, there is a
rate below which the TX800-Series sensor cannot read.
Check the flow rate table below for the minimum flow rate
detectable by the sensor for a given pipe size.