User guide

RevA MN300282 29of34
INSTALLATION(cont.) StepSeven
5. StandPipe:Astandpipemaybeusedtodampenturbulence orseparatesurfacefoamfromthepoint
ofmeasurementintheapplication.
a. Pipecanbemadeofanymaterial.
b. Selectaminimum3”IDpipeforthestandpipe.
i. A 2” pipe is usable with the LU77 series, but
thisistheminimumsize.
ii. Pipesizeslargerthan3”canalsobeused.
c. Use a coupling and reducer bushing to attach the
EchoSwitch®tothepipe.
i. With the LU77 series, use a plastic reducing
bushingsuchasLM52‐14002”Tx1”Tfittingor
theLM52‐14102”Sx1”Tfitting.
d. Thepipelengthshouldrunthemeasurementspanand
thebottomofthepipeshould remainsubmergedatall
timestopreventfoamfromenteringthepipe.
e. Cut a 45°notch at the bottom of the pipe and drill a
1/4”pressure equalization hole within the dead band
ofthesensor.
f. The pumps should not drive liquid past the open end
ofthestandpipewhichcausestheliquidinthepipeto
oscillate.



EchoSwitch®
LU77

2”x1”
Reducer
Bushing
(TxT)

2”Coupling
(SxT)

VentHole
(1/4”)

2”PVC
Pipe


LU77attachedtoaLM52‐1400
(2”x1”reducerbushing)and2”
Coupling(SxT).

Avoidtheuseofateewithinthe
standpipe.Ateecancreatefalse
signalsthatwillnegativelyeffect
thesensor’sperformance.

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