<![CDATA[Blog]]>https://piezus.com/blog/ Thu, 21 Nov 2024 06:37:29 +0000 Zend_Feed http://blogs.law.harvard.edu/tech/rss <![CDATA[Explosion proof pressure transmitter]]>https://piezus.com/blog/oQ2VPf06qZo/ 1. Hazardous area (hazardous area components)
2. Hazardous industrial facilities (examples of hazardous industrial facilities)
3. Types of explosion protection (intrinsically safe and explosion proof enclosure)

]]> Mon, 28 Nov 2022 13:58:00 +0000 <![CDATA[What is a pressure gauge?]]>https://piezus.com/blog/uVFK7Ydr6Ac/ What is a Pressure Gauge? 1. Pressure Gauge application 2. Pressure Gauge types and its operating principle (digital and mechanical pressure gauges 3. The pros and cons of mechanical and digital pressure gauges

]]> Tue, 29 Mar 2022 13:58:06 +0000 <![CDATA[Pressure transmitter mounting. Part 2. 4-20 mA electrical connection]]>https://piezus.com/blog/pressure-transmitter-mounting-part-2-4-20-mA-electrical-connection/ There is a number of most common output electrical signal types used to connect pressure transmitters to measurement instruments. The most popular one is a 2-wire 4-20mA current output.

1. Connecting cable to DIN 43650

The first step is to strip the wire ends of insulation and to tin them.

Connecting cable to DIN 43650 The first step is to strip the wire ends of insulation and to tin them.

2. Mounting DIN 43650 connector

Disassemble the connector. Pull the wire through the nut and the rubber sealing sleeve. Lead the wires through the connector housing and insert them into the corresponding pins of the terminal block.

Mounting DIN 43650 connector Disassemble the connector. Pull the wire through the nut and the rubber sealing sleeve.  Lead the wires through the connector housing and insert them into the corresponding pins of the terminal block.

3. Signal cable position rules

The layout of power supply and signal lines should prevent moisture from reaching the transmitter's cable gland. 

Signal cable positioning rules Do not use plumber’s hemp, teflon tape or other sealing materials when mounting the transmitter. Use manufacturer’s supplied seals only.

 Use shielded cables if there is a close proximity to power equipment.

The layout of power supply and signal lines should prevent moisture from reaching the transmitter's cable gland.  Use shielded cables if there is a close proximity to power equipment.

4. Electrical couplings connection rules

Please observe the following rules when connecting electrical couplings:

- cable's external diameter should match the cable gland used;

cable's external diameter should match the cable gland used; cable's external diameter should match the cable gland used;

- do not remove cable's sheath when pulling it through the gland;

do not remove cable's sheath when pulling it through the gland   do not remove cable's sheath when pulling it through the gland

 - use only the supplied (original) cable gland sealing, clean and without damage;

use only the supplied (original) cable gland sealing, clean and without damage; use only the supplied (original) cable gland sealing, clean and without damage;

- cable's sheath must be completely undamaged;

cable's sheath must be completely undamaged; cable's sheath must be completely undamaged;

- tighten protective caps of the glands securely;

tighten protective caps of the glands securely; tighten protective caps of the glands securely;

- avoid mounting the transmitter with cable gland pointing upwards;

avoid mounting the transmitter with cable gland pointing upwards avoid mounting the transmitter with cable gland pointing upwards

]]> Wed, 30 Jun 2021 08:00:00 +0000 <![CDATA[Pressure transmitter mounting. Part 1. Connecting to process]]>https://piezus.com/blog/pressure-transmitter-mounting-part-1-connection-to-process/ Proper mounting is essential for the longest service life of your pressure transmitter. 

1. Using valves and valve blocks

To simplify maintenance of pressure transmitters we recommend connecting them to process through valve manifolds. It ensures easy mounting and dismounting of the pressure transmitter with media disconnection.

Using valves and valve blocks To simplify maintenance of pressure transmitters we recommend connecting them to process through valve manifolds. It ensures easy mounting and dismounting of the pressure transmitter with media disconnection. It ensures easy mounting and dismounting of the pressure transmitter with media disconnection.

2. Connecting transmitter to process

Do not apply force to the transmitter housing with pliers when installing it. In most cases a hex wrench is the required tool to screw the transmitter in.

Connecting transmitter to process  Do not apply force to the transmitter housing with pliers when installing it. In most cases a hex wrench is the required tool to screw the transmitter in.

3. Pressure port seal

Do not use plumber’s hemp, teflon tape or other sealing materials when mounting the transmitter. Use manufacturer’s supplied seals only. 

Pressure port seal Do not use plumber’s hemp, teflon tape or other sealing materials when mounting the transmitter. Use manufacturer’s supplied seals only.

4. Mounting pressure transmitter into enclosed volume

Do not attempt to screw in the transmitter into the enclosed cavity filled with liquid. This may cause overpressure and the diaphragm damage. 

Do not attempt to screw in the transmitter into the enclosed cavity filled with liquid This may cause overpressure and the diaphragm damage.

Valve manifolds are recommended for such applications to ensure easy mounting.

Valve manifolds are recommended for such applications to ensure easy mounting.    Mounting pressure transmitter into enclosed volume

5. Using pressure snubber

Use of pressure snubbers is recommended for applications where sudden pressure increases and fluctuations are expected. 

Use of pressure snubbers is recommended for applications where sudden pressure increases and fluctuations are expected.  Using pressure snubber Use of pressure snubbers is recommended for applications where sudden pressure increases and fluctuations are expected.

 

]]> Tue, 29 Jun 2021 14:02:00 +0000 <![CDATA[What is pressure?]]>https://piezus.com/blog/TzjAJOURjR0/ What is pressure? 1. The Physical Quantity Pressure 2. Pressure units 3. Gas pressure 4. Hydrostatic Pressure of a Liquid 5. Atmospheric Pressure 6. Absolute, Gauge and Differential Pressure 7. Instrument for Pressure Measurement

]]> Fri, 09 Apr 2021 09:54:22 +0000 <![CDATA[What is a pressure switch?]]>https://piezus.com/blog/_pgAouwCJkI/ What is a Pressure Switch? 1. Pressure Switch operating principle (common pressure switch application) 2. Pressure Switch types (electronic and mechanical pressure switch) 3. The pros and cons of mechanical and electronic pressure switches

]]> Tue, 24 Mar 2020 13:47:00 +0000 <![CDATA[Submersible pressure transmitters installation ]]>https://piezus.com/blog/DFWQJk0x7pw/ Submersible Pressure Transmitter Installation

  1. Selection of installation location
  2. Submersible Pressure Transmitter Mounting (the use of special clamps: cable clamp with rubber sealing sleeve or cable hanger)
  3. Connecting submersible pressure transmitter to termination box (termination box installation; the use of hydrometric cable and regular cable)
]]> Wed, 25 Sep 2019 13:47:00 +0000 <![CDATA[Submersible pressure transmitters]]>https://piezus.com/blog/j9pnQQw9Dos/ Mon, 03 Jun 2019 13:47:00 +0000 <![CDATA[Pressure transmitter mounting. Part 2. 4…20 mA electrical connection]]>https://piezus.com/blog/_q0l_PwMuJU/ Mon, 28 Jan 2019 13:47:31 +0000 <![CDATA[Pressure transmitter mounting. Part 1. Connecting to process]]>https://piezus.com/blog/sE3gj15t31c/ Pressure transmitter mounting. Part 1. Connecting to process

1. Using valves and valve blocks

2. Connecting transmitter to process

3. Pressure port seal

4. Mounting pressure transmitter into enclosed volume

5. Using pressure snubber

]]> Mon, 28 Jan 2019 13:35:30 +0000 <![CDATA[What is a pressure transmitter (pressure transducer)?]]>https://piezus.com/blog/_fla9L6mSM0/ 1. Pressure: the physics.
2. Types of pressure (absolute, gauge, differential).
3. Types of pressure transmitters (set-in/submersible).
4. Design of pressure transmitters (mechanical connection (ports), sensor, electronic module, electrical connection).
5. Pressure transmitters: areas of application.

]]> Wed, 14 Mar 2018 14:18:21 +0000 <![CDATA[Accuracy of pressure transmitters: calculation of nonlinearity by BFSL or TPM]]>https://piezus.com/blog/Accuracy-of-pressure-transmitters-BFSL-TPM/ What is the difference between the nonlinearity calculated by TPM method and BFSL method?

The basic accuracy specified by manufacturers of pressure and level transmitters in their datasheets includes nonlinearity, hysteresis and repeatability. Very often, next to nonlinearity data you see "BFSL" and / or "TPM". These are two different approaches to calculating nonlinearity.

TPM – is the Terminal Point Method, see fig. 1.

BFSL – is the Best Fit Straight Line method, see fig. 2

Applied, the methods provide differing nonlinearity values. As a rule, BFSL gives values twice as low as those given by TPM. So what is the difference between these methods, and how do you compare the accuracy of pressure transmitters made by different manufacturers?

TPM

This method implies connecting end points of the real characteristic with a line ( green line on fig. 1). This line and maximum deviation of the real characteristic are the variables used to calculate maximun error. In figure 1 it is 0.5%.

Terminal Point Method (TPM)

Figure 1 (TPM)   

BFSL

The Best Fit Straight Line method implies determining the accuracy relative to the averaged line between the extreme deviations of the real characteristic (black line). In Figure 2, the maximum error is 0.25%. As a result, we have the maximum error twice as small as that calculated with the help of TPM.

Best Fit Straight Line Method (BFSL)

Figure 2 (BFSL)  

Very often, manufacturers mark the nonlinearity value as "BFSL", referring to IEC 61298-2. If there is no mark there, most likely, the value was calculated through TPM.

Comparing the accuracy of transmitters from different manufacturers, it is important to make sure that in both cases the value was calculated through the same method. Thus, you will avoid errors in comparing characteristics of pressure and level transmitters.

 

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