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Liquid Low Flow Meters

Liquid Low Flow Sensors

Rheotherm liquid flow meters are an excellent, and often times the only choice for reliable measurement of low flow rates.  For flow rates from 1 gallon/year (10 cc/day) to a few GPM, they provide repeatable flow measurement with little or no maintenance.  Options for hazardous locations (intrinsically safe/explosion-proof) are available. 

What Can We Measure?
Continuous flow of most homogeneous liquids and slurries, low or high viscosity.  Our flow meters have been used for everything from liquefied gases to thick oils and pastes.  Corrosive chemicals, light hydrocarbons, water and water-based fluids – Contact Us about any application you have.  

 

How Are They Installed?
These are in-line flow sensors typically installed with standard tube fittings, but optionally available with flanges, sanitary fittings, etc.  Any orientation is acceptable, except vertical with flow going down.  With some models the electronics are integral to the sensor, and other models have a separate electronics enclosure that can be installed up to 200 feet from the sensor. Electronics Options

What Is the Turndown Ratio?
Typical calibration ranges are 10:1 (options up to 200:1), with good accuracy over the entire range.  The sensors cannot be damaged by overranging. 

How Do They Work?
Our low flow meters use either a straight-through or looped flow tube with a heated and an unheated RTD attached to the outside of the tube.  The temperature differential between the two RTDs provides the primary flow signal;  at high flow rates the differential is lower as flow removes more heat, and at low flow rates the differential is higher, as flow removes less heat.  Nothing touches the fluid except the flow tube wall, and there are no mechanical parts to wear, stick or break.  More on Method of Operation (PDF)

How Do I Get One?

Submit your inquiry today to send us the application data to review, or visit our contact us page for telephone, fax and email information.

TU and TUL Sensor Specifications

	Standard	Options
Service	Most homogeneous liquids, slurries
Wetted Surface	316 SS	Alloys 276, 200, 400, 600, 800, 20; 316L SS, titanium, tantalum, quartz
Turndown Ratio	10:1	200:1
Process Connection	Tube stubs	Flanges, NPT, sanitary, other
Max. Temperature	140ºF (60ºC)	Up to 350ºF (177ºC)
Max. Pressure	500 psi	Up to 10,000 psi
Location	General purpose	Hazardous (CL I, Div. 1, Grp BCD)
Sizes	Capillary, 1/16, 1/8, 3/16, 1/4, 1/2, 5/8, 3/4, 1	Consult factory
Accuracy (with electronics)	+/- 1% of reading
Repeatability	+/- 0.5%

TU and TUL Sensor Flow Rates

(Typical calibration is for 10:1, up to 200:1, range within these limits)

Flow Rate	Tube Size
	C	1/16	1/8	3/16	1/4	3/8	1/2	5/8	3/4	1
Maximum - GPM (cc/min)	.00053 (2)	.0159 (60)	.1321 (500)	.4 (1500)	1 (3800)	2.5 (1900)	5 (9500)	8 (3000)	10 (38000)	20 (76000)
Minimum – GPM (cc/min)	2E-8 (.007)	1.3E-5 (.05)	7.9E-5 (3)	.002 (8)	.006 (23)	.01 (38)	.02 (76)	.07 (265)	0.1 (379)	0.2 (760)

 

Rheotherm Flow Meters Electronics Options

More information about Rheotherm low flow meters (PDF)