SRV/SRD Specifications related FAQs

Find answers to the SRV/SRD Specifications related questions in this section – Operating Environment, Mechanical, Material Compatibility, Safety Approval, Shipboard Approval, Marketing & Branding, Installation & Use.

Operating Environment Specifications

What are the interdependencies between Pressure & Temperature range limits for the devices? i.e. can the instrument withstand 200 ⁰C and 5000 psi together? Please provide info on the pressure & temperature options that cannot go together. If there are certain other dependencies on Pressure/Temperature ranges, like limited Viscosity measurement range availability at higher pressure and/or temperature, please specify.

Both SRV and SRD are available in a HPHT variants that can withstand 200°C fluid temperature at 5000 psi. Max. temperature allowed at the back-end (electrical connector side) is 180°C for the HPHT version of SRV/SRD.

Does the Direct Meter Mount (solid tube between sensor & electronics) version for SRV/SRD share the same pressure and temperature spec limitations as the remote (via cable) meter mount version?

Direct mount is not yet available commercially, only in demo version. It will share the same P/T spec. It is not currently low on our priority list for release as majority of our customers prefer the cable version.

When mounted inline (withstanding radial flow), what are the limitations with regards to minimum & maximum flow rates? What are the limitations with other mounting arrangements?

No effect of mounting configuration or flow rates on the sensor performance. Tested in our flow loop to 32 l/s (80 m3/hr, 350 gpm). Higher flow rates in customer flow loops.

Material Compatibility Specifications

Have you had any experience with exotic materials (e.g. Hastelloy-C, Inconel, Monel, other alloys) for process wetted parts?

No, however it is possible – we have explored in past based on customer enquiries but have not manufactured any. Two materials we are very familiar with are 316L and Titanium.

Are any elastomers or O-rings used to isolate any part of the sensor from the process or the outside environment?

No elastomers or o-rings needed for the SRV, SRD and DVP – direct metal to metal process connection.

Mechanical Specifications

What are the extension length sizes/limitations for the Direct meter mount version of SRV/SRD instruments?

No limitation, the sensor cable at the moment is supplied by us up to 100 feet (30m) length. Direct mount can have as long an extension as needed.

What are the allowable limits for solids contamination (particle size, concentration) in process fluid? Have you had experience with installing and using the instruments in slurry type applications?

No effect seen so far in multiple slurry applications but we have not run any dedicated experiments in our lab to check the effect in flow loops (stationary yes, without any effects). We have multiple successful customer installs in fairly solid-laden slurries in chemicals, and food processing applications.

Safety Approval Specifications

What are the exact Safety Approvals (ATEX / IECEx) markings the instrument can carry? If none, what is a realistically achievable target?

Both certifications available.

For the CE certification, which specific CE standards and directives do SRV/SRD devices comply to. Please share Declaration of Conformity cert if available.

CE directives that all rheonics products comply to:

  • EMC Tests (EN 61326-1, EN 61326-2-3)
  • Electrostatic discharge (ESD), IEC 61000-4-2
  • Electromagnetic field, IEC 61000-4-3
  • Burst, IEC 61000-4-4,
  • Surge, IEC 61000-4-5
  • Conducted RF, IEC 61000-4-6
  • Conducted disturbances, EN 55011
  • Electromagnetic radiation, EN 55011
  • EN300328 – Electromagnetic compatibility and Radio spectrum Matters (ERM); Wideband transmission systems; Data transmission equipment operating in the 2,4 GHz ISM band and using wide band modulation techniques;
  • EN301489 – Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 1: Common technical requirements


Last two are for the Bluetooth module that we have in the transmitters. We comply with FCC (pre-certified modules).

Shipboard Approval Specifications

What stage is at the DNV-GL Shipboard approval process and what do you see as a realistic target date to receive DNV-GL certification?

Pre-test done hardware ready for certification (table of tests done below) àawaiting production facility preparation for audit. Timeline (depends on Ex certs priority): 3 months – best case, worst case – depends on any issue that DNV-GL raises with production management system. Our priority for marine market is low at the moment but we started the process to run it together with the CE tests.

DNV-GL tests performed and all passed

Electrical Power Supply Failure Test CG 0339, [4]
Power Supply Variations Test CG 0339, [5]
Vibrations Test CG 0339, [6]
Dry Heat Test CG 0339, [7]
Damp Heat Test CG 0339, [8]
Cold Test CG 0339, Section 9
Insulation Resistance Test CG 0339, [12]
High Voltage Test CG 0339, [13]
Conducted Low Frequency Immunity Test CG 0339 [14.4]
Electrical Fast Transient/Burst Immunity Test CG 0339 [14.5]
Electrical Slow Transient/Surge Immunity Test CG 0339 [14.6]
Conducted Radio Frequency Immunity Test CG 0339  [14.7]
Radiated Electromagnetic Field Immunity Test CG 0339,  [14.8]
Electrostatic Discharge Immunity Test CG 0339, [14.9]
Radiated Emission Test CG 0339 [14.11]
Conducted Emission Test CG 0339  [14.12]
Marketing and Branding

Do you see any issues if any company opts to sell and market SRV/SRD under a private label?

Depends on market/business agreement. Co-branding would be our preference.

Installation and Use

Have you replaced an Emerson or a VAF unit in a working process installation? If so, how was retrofitting existing process connection handled?

Replaced by our clients – marine system integrators. We heard it multiple times that installing rheonics sensors was simpler and cheaper than either of the other two.

For Marine Installations, is SRV device a drop-in replacement without changing the standard pipe spool housings that contain VAF and/or Emerson devices?

No, a simple adapter (Swagelok to NPT) is needed as VAF/EMR installations use a cone-seat compression connection. Possible to make a drop-in version of the SRV for marine market with cone-seat compression connection.