RHM 10

FLOW SENSOR

The Model RHM 10 is perfect for small scale production with continuous low flow and small batch dispensing requirements. With a variety of construction styles, the RHM 10 is ideal for countless flow applications.

Range: 0.25 kg/min up to 90 kg/min
Pressure: up to 1384 bar (20073 psi)
Temperature: -196°C (-321°F) up to +350°C (662°F)
Accuracy: 0.1 % of rate
Materials: SS 316L / SS 316Ti, Super Duplex – 1.4410, Sandvik HP160, Alloy C22 – 2.4602, Tantalum – UNS R05200
Process Connection: ½" up to 1 ½"

CONFIGURE

CATEGORY Medium Size Sensors, H2 Filling Station, 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 316L (standard)	208 bar 3017 psi	185 bar 2683 psi	156 bar 2263 psi	133 bar 1929 psi
Alloy C22	341 bar 4945 psi	303 bar 4394 psi	258 bar 3741 psi	214 bar 3103 psi
Super Duplex Low Pressure	481 bar 6976 psi	448 bar 6498 psi	402 bar 5831 psi
Sandvik HP160® Low Pressure	600 bar 8702 psi	540 bar 7832 psi	490 bar 7107 psi
Super Duplex Medium Pressure	753 bar 10921 psi	701 bar 10167 psi	629 bar 9123 psi
Sandvik HP160® High Pressure	1010 bar 14649 psi	970 bar 14069 psi	650 bar 9472 psi
Super Duplex High Pressure	1379 bar 20000 psi	1289 bar 18695 psi	1156 bar 16766 psi
Tantalum	73 bar 1059 psi	56 bar 812 psi	45 bar 653 psi

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: 0.00246 kg/min (0.00542 lbs/min).
• Zero point stability of a premium sensor with high accuracy or focused calibration: 0.0012 kg/min (0.00265 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:

• ±0.000556% of maximum flow per °C
• ±0.000333% of maximum flow per bar

Process temperature effect on density:
• Additional uncertainty of ±0.000122 g/cm³ per °C difference from calibration temperature with standard density calibration.
• Additional uncertainty of ±0.000036 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.