RHM 15

FLOW SENSOR

The RHM 15 is an all-purpose meter suitable for liquid processing plants. A wide application flow range capability allows for commonality of installation across numerous lines – a real benefit to owners and operators.

Range: 0.5 kg/min up to 240 kg/min
Pressure: up to 1282 bar (18593 psi)
Temperature: -196°C (-321°F) up to +350°C (662°F)
Accuracy: 0.1 % of rate
Materials: SS 316L / SS 316Ti, Alloy C22 – 2.4602, Super Duplex – 1.4410, Tantalum – UNS R05200
Process Connection: ¾" up to 2 ½"

CONFIGURE

CATEGORY Medium Size Sensors, Chemical Injection, Fuel Consumption, Oil Measurement, Painting/Coating Lines, Plastics Production

Performance Data

Flow Measurement Uncertainty
Standard: 0.20 % of rate
Enhanced: 0.15 % of rate
Premium: 0.10 % of rate
Ultimate: 0.05 % of rate – requires RHE 40 Series transmitter
Low Flow Calibration: 0.10 % of rate – requires RHE 40 Series transmitter
Customized Calibration: Consult factory

Low flow calibration focuses on the range from ½ × Qₙₒₘ downwards to lower flow rates than on other calibrations. Often used for low pressure gas or very viscous liquids. Customized calibration uses specific calibration points according to customer requirements.

Flow Measurement Repeatability
Standard Sensors: ±0.1 % of rate
Premium Sensors: ±0.05 % of rate

Temperature Measurement
Better than ±1 °C

Density Calibration (Liquid)
Standard: ±0.001 kg/l uncertainty
Premium: ±0.0005 kg/l uncertainty – requires High Accuracy or Focused Calibration Option

Reference conditions: 18–24 °C Water @ 1–3 bar

Measurement Tube Pressure Ratings

The maximum pressure (pₘₐₓ) of a sensor is determined by its lowest rated part: the measurement tube (see table below), the connection block (see datasheet) or the process connection (see corresponding standards or manufacturer information).

If applicable, the material of a connection block is always SS 316L. For sensors in sealless versions, the material of the process connection is usually the same as the material of the measurement tubes. In special cases, the material may differ.

	50 °C 122 °F	120 °C 248 °F	210 °C 410 °F	350 °C 662 °F
SS 316Ti (standard) Low Pressure	161 bar 2335 psi	149 bar 2161 psi	135 bar 1958 psi	117 bar 1696 psi
SS 316Ti (standard) High Pressure	389 bar 5642 psi	359 bar 5206 psi	326 bar 4728 psi	283 bar 4105 psi
Alloy C22	246 bar 3568 psi	218 bar 3162 psi	185 bar 2683 psi	154 bar 2234 psi
Super Duplex * Low Pressure	842 bar 12212 psi	783 bar 11357 psi	702 bar 10182 psi
Super Duplex * High Pressure	1375 bar 19943 psi	1206 bar 17492 psi	1090 bar 15809 psi
Tantalum	81 bar 1175 psi	63 bar 914 psi	51 bar 740 psi

* Minimum operating temperature for Super Duplex stainless steel is -40 °C. Maximum pressure may be lower depending on the design type.

Uncertainties and flow measurement turn-down

The turn down capability from Qₙₒₘ of the flow sensor is driven mainly by its zero point stability. At the very low end of the measuring range the uncertainty (u) is dominated by zero point stability.

• Zero point stability of a standard sensor with general accuracy calibration: 0.0039 kg/min (0.0086 lbs/min).
• Zero point stability of a premium sensor with high accuracy or focused calibration: 0.0016 kg/min (0.0035 lbs/min).
• uncertainty = calibration uncertainty, if: flow ≥ (zero point stability / (base uncertainty/100))
• uncertainty = (zero point stability/Q)*100, if: flow < (zero point stability / (base uncertainty/100))

Uncertainties from environmental and process conditions

If sensors are not zeroed at operating conditions, minor additional uncertainties can arise from elevated temperatures and pressures:

• ±0.00053% of maximum flow per °C
• ±0.00042% of maximum flow per bar

Process temperature effect on density:
• Additional uncertainty of ±0.00013 g/cm³ per °C difference from calibration temperature with standard density calibration.
• Additional uncertainty of ±0.00011 g/cm³ per °C difference from calibration temperature with enhanced density calibration.
• This effect can be mitigated by a simple field density adjustment at operating conditions.

Process pressure effect on mass flow:
• The effect of pressure on flow measurement is 0.0001% of rate per bar. Compensation is possible by pressure sensor input (analog input or digital write) or manual value entry into the transmitter.

Process pressure effect on density:
• The effect of pressure on density measurement is 0.000075 g/cm³ per bar. Compensation is possible by pressure sensor input (analog input or digital write) or manual value entry into the transmitter.

Applying Premium calibration to higher pressure, special materials and/or non-standard temperature models may show higher zero uncertainties (up to 3 times higher than standard sensor).

Couldn’t find what you were looking for?

Other wetted materials may be possible for chemical compatibility, lower pressure drop, abrasion allowance or other application specific requirements. Rheonik can provide nearly any material for the wetted parts.