---
title: Best Practices for Wet-to-Wet Differential Pressure Measurements
description: Best Practices for Wet-to-Wet Differential Pressure Measurements
---

[Setra Blog ](https://www.setra.com/blog)

# [Best Practices for Wet-to-Wet Differential Pressure Measurements](https://www.setra.com/blog/best-practices-wet-wet-differential-pressure-measurements/2013/05/30)

 Written by [Tom Lish](https://www.setra.com/blog/author/tom-lish) | May 30, 2013

**For high line pressure, high differential pressure applications**

The pressure difference across an orifice plate, filter, pump, valve, etc. can be sensed with two pressure transducers such as the [Model 206](https://www.setra.com/products/pressure/gauge-pressure-transducer-model-206/). One transducer measures the high side pressure (P1) while the other measure the low side pressure (P2). Pressure media can be any liquid or gas compatible with 17-4 pH stainless steel.

**Advantages: **1. Can readout P1, P2, and ΔP (P1 - P2)  
2. Can take full line pressure either side (for P)  
3. No organic seals or gaskets, etc.  
4. Can reduce pressure piping by placing each transducer near its pressure source.

**Option A:**  
 Provides a two wire differential analog output proportional to differential pressure.  
 Applicable ratios of line pressure to [differential pressure](https://content.setra.com/whitepaper-advancements-wet-wet-pressure-sensing), analog output and accuracy are:

| **Pressure Ratio** | **Analog Output** | **Accuracy** |
| --- | --- | --- |
| 1:1 | 0 - 5.00 VDC | ± .16% Full Scale |
| 2:1 | 0 - 2.50 VDC | ± .32% Full Scale |
| 3:1 | 0 - 1.67 VDC | ± .48% Full Scale |
| 4:1 | 0 - 1.25 VDC | ± .64% Full Scale |
| 5:1 | 0 - 1.00 VDC | ± .80% Full Scale |

Pressure Ratio = Line Pressure/Differential Pressure

Both Model 206 transducers must have identical full scale pressure ranges equal to or greater than the maximum line pressure.

**Example: **Line pressure = 100 psig

Differential pressure = 50 psid

Pressure ratio = 100/50 = 2:1  
 Specify two Model 206, 0-100 psig transducers.

The signal proportional to differential pressure is read between (+) signal #1 and (+) signal #2.

**Option B:**  
 Provides a two wire ground referenced 0 to 5 VDC analog output for both the high side pressure (P1) and the low side pressure (P2). It is possible to monitor P1, P2, and P (P1 - P2) on a readout such as a digital panel meter, datalogger, scanner or recorder. The P (P1 - P2) subtraction can be performed in systems software or by using an external subtraction circuit.

 

 

 

 

 

 

 

[Learn more about new advancements in wet-to-wet pressure sensing with remote sensors](https://content.setra.com/whitepaper-advancements-wet-wet-pressure-sensing).

[View full post](https://www.setra.com/blog/best-practices-wet-wet-differential-pressure-measurements/2013/05/30)

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