Red Meters vs Pisonics PS7000 — Deflection Sensing or Acoustic Impedance
Red Meters weighs the pipe. Pisonics reads the slurry. The most consequential difference between them is not accuracy — it is that Red Meters must be installed horizontally, and horizontal is the orientation where slurry stratifies.
Feature comparison
| Feature | Ultrasonic Slurry Density Meter | Red Meters Rugged Series |
|---|---|---|
| Principle | Ultrasonic acoustic impedance, chirp pulse-echo | Inline pipe deflection, laser displacement readout ¹ |
| Accuracy | ±1 % FS; the datasheet publishes ±1 % mass concentration | ±0.5 % of full scale ¹ ² |
| Repeatability | Not published | ±0.3 % FS (datasheet) / ±0.4 % (website) ¹ ³ |
| Density range | 0–80 % mass concentration | Not published ⁴ |
| Pipe size | DN50 – DN1000 (larger on request) | 50–1000 mm (2"–40") ¹ |
| Process temperature | 0 – 80 °C standard; 120 °C high-temperature version to order | 0 – 110 °C ¹ |
| Process pressure | ≤ 1.6 MPa standard | 0–300 PSI (4"–40"); 0–70 PSI (2"–3") ¹ |
| Vacuum service | Not restricted by the measurement principle | Explicitly excluded below 0 PSI; a vacuum relief valve is supplied and must be fitted ¹ |
| Mounting orientation | Vertical preferred, flow upward; horizontal permitted with the probe on the horizontal diameter of the pipe | Horizontal only. A slight incline is acceptable. Vertical installation is not permitted ¹ |
| Ingress protection | IP65 | IP67 ¹ |
| Hazardous area | Ex d IIC T6 Gb optional | Not published ⁴ |
| Update rate | Configurable | 1 Hz ¹ |
| Entrained air | Keeps measuring in bubbly slurry; outputs a 0–100 aeration index and a bubble flag | Not addressed in published material ⁴ |
| Calibration | Multi-point field regression, up to 20 points, online, no shutdown; r² acceptance check from 3 points | Factory calibrated; field verification at installation ¹ |
| Additional outputs | Aeration index, echo energy, signal quality, probe temperature, fault status word | Temperature, pressure, vibration, liner wear, mass flow, % solids ¹ |
| Communication | 2 × 4–20 mA (NAMUR NE43), RS485 Modbus-RTU, HART 5, Bluetooth 5.4 BLE, Profibus-DP optional, 4G cloud optional | 6 × 4–20 mA, Modbus TCP/IP ¹ |
Competitor parameters cited from Red Meters Rugged Series datasheet.
Takeaway
How the two measurements differ
Red Meters: "Our system works by measuring the deflection of your pipe as material flows through it. As the weight of the material changes, our advanced sensors detect subtle variations." Displacement is read optically — the current datasheet specifies a Class 1 laser (FDA CDRH Part 1040.10). (Manufacturer statement, redmeters.com/how-it-works.)
PS7000: acoustic impedance at a wetted probe mounted flush with the pipe bore.
Note on accuracy. On the full-scale metric these are directly comparable and Red Meters is the tighter figure: ±0.5 % of full scale against our ±1 % FS. Our datasheet separately publishes ±1 % mass concentration, a different metric that cannot be converted into either. A full-scale percentage grows in absolute terms as the range widens, so ask both vendors to state accuracy against your range and your medium.
General advice on certification claims. Whichever instrument you shortlist, ask the vendor for the certificate itself rather than a citation of it. Third-party trade coverage of this product category frequently paraphrases certification status in ways the manufacturers' own documentation does not support — ours included.
About entrained air. The PS7000 is designed to keep measuring in bubbly slurry — that means a stable reading in the presence of gas, not a guarantee of accurate density at any gas fraction. The probe face must not be covered by a continuous gas phase: a gas film, a gas pocket or an empty pipe stops the measurement rather than biasing it. The entrained-air index exists so the control room can see which of those two situations it is in.
About the Ex rating. The PS7000 datasheet states Ex d IIC T6 Gb (option, to be specified when ordering) and does not name a certification body. Please confirm the certification scheme required in your target market with us before treating this as equivalent to an ATEX or IECEx certificate.
When to choose Red Meters
- The line is horizontal, well above deposition velocity, and stratification is not a concern. Full-cross-section weight sensing is not affected by near-wall conditions.
- Liner wear monitoring has real value to you. Red Meters outputs it as a live variable; that is a genuinely useful differentiator on abrasive duty.
- Tighter published accuracy on the full-scale metric. Red Meters states ±0.5 % of full scale against our ±1 % FS. If that one number decides the order, it decides it in their favour.
- Acoustically awkward media. A weight-based measurement is indifferent to the sound velocity and scattering behaviour of the slurry.
When to choose the PS7000
- You want vertical installation. This is the big one. For slurry, vertical flow-upward is the orientation that resists stratification and settling, and it is the position we recommend. Red Meters states vertical installation is not permitted, so on a settling-prone slurry you are being pushed toward the riskier orientation.
- The line ever sees vacuum. Red Meters excludes sub-atmospheric service outright.
- The area is classified. Red Meters publishes no Ex rating.
- You need a published density range before ordering. Red Meters does not publish one.
- Entrained air is present. Not addressed in Red Meters' published material.
- You cannot install a spool piece. The PS7000 offers a weld-in boss on the existing pipe.
FAQ
Why does mounting orientation matter so much for slurry?
Below the critical deposition velocity a horizontal slurry line stratifies — dilute at the top, dense at the bottom. A full-bore weight measurement still reads the correct total mass in that condition, so Red Meters is defensible here. But stratification usually signals a process problem you want to know about, and vertical flow-upward avoids it in the first place. If your velocity margin is thin, orientation flexibility is worth more than a decimal place of accuracy.
Does the deflection cartridge restrict flow?
Red Meters states it does not: the cartridge bolts into the pipe section and media pass through as in a standard section.
Sources
- Manufacturer statement — Red Meters Rugged Series datasheet Rev. 20260629 and website, accessed August 2026.
- Earlier third-party coverage (2017) cited ±0.25 % of reading for the RM series. Of reading and of full scale are different metrics, and the product generation has changed. Do not compare the two figures.
- Website and datasheet disagree on repeatability.
- Not published as of August 2026.
Competitor facts verified August 2026, all from the manufacturers' own websites, official PDF datasheets or officially hosted documents. PS7000 figures are from PS7000_技术规格书_中文.pdf Rev. A · 2026-08 (PS7000-DS-ZH-A). Manufacturers revise published data without notice — please re-check before relying on any figure here.
Talk to us
Pisonics — Xi'an Pisonics Information Technology Co., Ltd.
15B016, Block A, Olympic Building, Chang'an North Road,
Beilin District, Xi'an, Shaanxi 710061, China
+86 159 0293 2017 | info@pisonics.com | www.pisonics.com
Send us pipe size, orientation, slurry velocity, particle size distribution and whether the line carries entrained air — we will tell you whether an acoustic measurement holds up on your line, or which principle fits better.