Formulas - Inst Tools

4-20mA Linear Conversion Calculation for VFD Drive (Formula)

Editorial Staff — Mon, 03 Jun 2024 07:00:10 +0000

4-20mA linear conversation calculation for VFD Drive and conversion Formula and with Example table. Download the Excel file.

The post 4-20mA Linear Conversion Calculation for VFD Drive (Formula) appeared first on Inst Tools.

Instrumentation Basics – Range Conversion Formula and Examples

Editorial Staff — Wed, 15 Jun 2022 05:11:28 +0000

In this article, you will learn the instrumentation basics and transmitter range conversion formula, and industry examples.

The post Instrumentation Basics – Range Conversion Formula and Examples appeared first on Inst Tools.

Instrument Percent of Span Error

Editorial Staff — Mon, 20 Jan 2020 04:39:15 +0000

An important part of performing instrument calibration is determining the extent of an instrument’s error. Error is usually measured in percent of span. Instrument Percent of Span Error Calculate the percent of span error for each of the following examples, and be sure to note the sign of the error (positive or negative): Question 1: […]

The post Instrument Percent of Span Error appeared first on Inst Tools.

How to do 4-20mA Conversions Easily

Editorial Staff — Sun, 21 Apr 2019 13:24:41 +0000

Generally it is possible to generate a “custom” linear equation in the form of y = mx + b for any linear responding instrument relating input directly to output, a more general approach may be used to relate input to output values by translating all values into (and out of) per unit quantities. A “per unit” quantity is simply […]

The post How to do 4-20mA Conversions Easily appeared first on Inst Tools.

Example of 3-15 psi to 4-20mA Conversion

Editorial Staff — Sat, 20 Apr 2019 05:38:55 +0000

A current-to-pressure transducer is used to convert a 4-20 mA electronic signal into a 3-15 PSI pneumatic signal. This particular transducer is configured for reverse action instead of direct, meaning that its pressure output at 4 mA should be 15 PSI and its pressure output at 20 mA should be 3 PSI. Calculate the necessary […]

The post Example of 3-15 psi to 4-20mA Conversion appeared first on Inst Tools.

PLC Raw Count Calculation for Pressure Transmitter

Editorial Staff — Fri, 01 Mar 2019 08:15:31 +0000

Every instrument has at least one input and at least one output. For instruments responding linearly, the correspondence between input and output is proportional: PLC Raw Count Calculation A practical example of this is a pressure transmitter, in this case one with an input range of 0 to 1023 PSI and an output of 4-20 […]

The post PLC Raw Count Calculation for Pressure Transmitter appeared first on Inst Tools.

4-20mA Formulas and Examples

Editorial Staff — Thu, 28 Feb 2019 09:58:19 +0000

4-20 mA transmitter current output can be converted to the voltage within a specified range, from 0 to a maximal amplitude Vmax, as shown in the following picture: 4-20mA Formulas Calling I the output current and V the Voltage—or other physical variables (PV) —between Vmin (which is usually 0) and Vmax; the conversion formulas are as follows: […]

The post 4-20mA Formulas and Examples appeared first on Inst Tools.

PLC Analog Input Conversion Formula

Editorial Staff — Sun, 16 Dec 2018 10:58:23 +0000

For any unit conversion on any PLC, you can use four function math with the following for PLC Analog Input Conversion Formula, which assumes integer math, as follows : PLC Conversion Formula Formulas: EU = ((EUSpan x (DATA – DataOffset))/DataSpan) + EUOffset ProcessValue = EU / FACTOR DataOffset = Data in input register at 4 […]

The post PLC Analog Input Conversion Formula appeared first on Inst Tools.

PLC Problems Troubleshooting

Editorial Staff — Sun, 16 Dec 2018 03:47:48 +0000

Troubleshooting PLCs can be started by checking the healthiness status of CPU, I/O Modules, Fuse Blow-out and different PLC Failure reasons including wiring, field transmitters healthiness status or transmitter configuration, check for any effect of induction voltage due to high voltage electrical cables etc. and many more reasons. The below scenario is one of the […]

The post PLC Problems Troubleshooting appeared first on Inst Tools.

PLC Analog Input Scaling

Editorial Staff — Thu, 13 Dec 2018 09:50:03 +0000

An Allen-Bradley SLC500 programmable logic controller (PLC) uses a 16-bit analog-to-digital converter ( in its model 1746-NI4 ) in analog input card to convert 4-20 mA signals into digital number values ranging from 3277 (at 4 mA) to 16384 (at 20 mA). However, these raw numbers from the PLC’s analog card must be mathematically scaled […]

The post PLC Analog Input Scaling appeared first on Inst Tools.