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Practical guides from the Instranova engineering team on selecting and applying process instruments – written from real product data and field experience. New guides are added here.
Make a tank strapping chart for horizontal, vertical or rectangular tanks, with the formulas, API MPMS strapping methods and how to load it into a level gauge.
How to read P&ID instrumentation symbols per ISA-5.1: tag letters, bubble shapes, location bars and signal lines, and why a DP transmitter can be FT, LT or PDT.
How a wireless level transmitter works, how LoRaWAN, NB-IoT and WirelessHART compare, what sets battery life, and the barometric error of sealed gauge cells.
Pressure transmitter for level measurement: worked LRV and URV for open tanks, dry and wet legs and remote seals, plus the density and temperature errors.
How an industrial laser level sensor works, its spot size, clear liquid, dust and foam limits, how it compares with 80 GHz radar, and where laser fits.
Ultrasonic vs radar level sensor, compared with numbers: sound speed and steam errors, beam spot, blind zone, dielectric limits and a selection table.
How a displacer level transmitter works, with dry calibration weights, water-equivalent wet calibration, interface span, density error and retrofit options.
Bubbler level measurement explained with worked math: head to mA, purge friction error by tubing size, supply pressure, closed tanks and two-tube density.
How a flow switch is drawn: P&ID tags FS, FSL and FSH, the flagged ladder contact at no flow, NEMA vs IEC symbols and how NO and NC map to SPDT terminals.
How to choose a water flow switch for sprinkler risers, pump protection, chiller loops and boilers: set points, tamper vs waterflow, lead-free parts and tests.
How a paddle flow switch works, published set points by pipe size converted to velocity, a worked sizing example, paddle trimming, installation and limits.
What a flow switch is and how it works: paddle, piston, thermal and sprinkler types, setting the trip point with deadband, fail-safe wiring and installation.
Bar to psi conversion chart from 0.1 to 1,000 bar, with psi to bar, EN 837 gauge ranges in psi, barg vs bara, and the shortcuts that cause conversion errors.
Vacuum pressure gauge scales and compound ranges explained: inHg and kPa conventions, catalog steps from 30-0-15 to 30-0-300 psi, accuracy math and selection.
How to specify a hydraulic pressure gauge: range rules for spikes and pulsation, snubber types, NPT vs G threads, test points and kits, and failure signs.
Boiler pressure gauge guide: normal readings for hydronic, combi and steam boilers, ASME dial range rules, tridicator altitude scales and siphon rules.
How to calibrate a pressure gauge: acceptance bands from the accuracy class, reference ratios, DKD-R 6-1 points and cycles, a worked as-found table and records.
Why pressure gauges are filled with glycerin, when silicone or halocarbon is required, the 300 psi venting rule and cold weather numbers per fill fluid.
Read a pressure gauge in three steps: find the unit, value each graduation and read square on. Worked psi, bar, MPa and vacuum examples with error bands.
Thermistor vs thermocouple vs RTD in real numbers: sensitivity, ranges, tolerance classes, self-heating, lead-wire error and which instrument inputs take each.
A thermocouple is one junction making about 30 mV; a thermopile stacks about 25 for 750 mV. How to tell them apart, the test values and the IR sensing side.
Grounded, ungrounded and exposed thermocouple junctions compared: real response times, ground loop arithmetic, insulation specs, and how to test and order.
How to test a thermocouple with a multimeter: resistance by wire gauge, millivolt checks, loaded pilot values, fault isolation and burnout alarm limits.
Extension grade or compensating cable, the X and C codes by type, resistance per gauge, how far a run goes before the instrument objects, and polarity checks.
ANSI and IEC thermocouple color codes by type, the legacy BS and DIN charts, the colors that collide between standards, and how to verify a doubtful one.
Type S, R and B platinum thermocouples compared: ASTM and IEC ranges, tolerance classes worked out in degrees, output, contamination and cable codes.
Type J, T and E thermocouples compared: ASTM and IEC temperature ranges, tolerance crossover points, output per degree, AWG limits and the color codes.
Type K thermocouple ranges explained tier by tier, ASTM and IEC tolerances with worked numbers, drift mechanisms, extension wire rules and a bench check.
A thermocouple is a temperature sensor made of two dissimilar metal wires. See how the Seebeck effect, cold junction compensation and junction styles work.
Flow meter cost runs from $50 rotameters to $20,000 Coriolis systems. Checkable US distributor price bands by technology, six cost drivers, and installed cost.
How to verify a Chinese instrument supplier in three layers: the company registry, each certificate against its issuer, and the instrument on a factory test.
HART vs Modbus vs plain 4-20 mA at the spec level: what the host needs, power and wiring, update rate and cable limits, Modbus pitfalls and spec lines to copy.
Saturated and superheated steam properties side by side, with the density arithmetic that makes an uncompensated steam flow meter read 33 percent high.
How to detect compressed air leaks, size the total leak load with a flow meter or receiver test, and convert cfm into money with DOE and ISO 11011 figures.
Paperless chart recorder specs explained: channels, accuracy basis, scan versus record interval, memory in recording days, Part 11 clauses and AMS2750 numbers.
Tank gauging for bulk storage: innage, outage and ullage, a worked TOV to NSV chain, the OIML R 85 limits of 1 mm and 4 mm, and what one millimeter costs.
Mechanical water meters wear and miss low flows; digital ultrasonic meters register drips and hold accuracy for years. Standards, numbers and how to choose.
How capacitive fuel level sensors work, output conventions from 240-33 ohm to CAN bus, accuracy specs compared, and why ethanol blends and water skew readings.
Vertical flow meter installation rules by type: why liquids must flow upward, when downward flow works, the rotameter exception, DP head math and straight run.
How a Karman vortex air flow sensor works, which Mitsubishi, Toyota and Lexus models used it, how to test a failing unit, and its industrial vortex cousins.
How dielectric constant sets radar echo strength: Fresnel math with worked numbers, minimum values by radar type, a media table and interface rules.
Coke oven gas flow measurement: composition, Nm3 correction, MW from heating value, sound speed at 60 percent hydrogen, naphthalene fouling, meter per point.
Beer flow meters do two jobs: sanitary process metering in the brewery and digital pour counting at the tap. Real accuracy numbers, prices and keg math.
Where to meter refrigerant flow: subcooled liquid line rules, mass flow math from cooling capacity, a technology selection table, and charge accounting rules.
Why foam and entrained air wreck flow readings: how each meter type fails, drive gain and density as gas detectors, and piping that sheds gas before the meter.
How to meter ammonia in each form: why magnetic meters fail on anhydrous NH3, vapor pressure and materials rules, and a technology comparison with accuracy.
How to choose an LPG or propane flow meter: liquid line vs vapor line, flashing and vapor pressure, mass vs corrected volume, custody approvals and materials.
How to measure molten salt level in CSP tanks and salt baths: GWR probes, cooled radar, DP seals and bubblers, plus the math turning level into tonnes and MWh.
How blast furnace stockline level is measured: 80 GHz FMCW radar vs sounding rods and isotopes, purge air specs, mounting geometry, and commissioning checks.
Cooling tower water level control compared: float valve, conductivity probes and continuous sensors, setpoint stack, makeup sizing math and freeze protection.
How a transformer oil level indicator works: magnetic gauge, 25 C and +20 C reference marks, expansion math, alarm contact ratings and continuous sensors.
How to measure well water level: sounder, wetted tape, air line and submersible transducer methods with worked math, drawdown diagnostics and casing volume.
How river water level is measured: radar, pressure, bubbler and float methods with real accuracy numbers, datum math, flood alarm stages and power sizing.
How to measure level in underground tanks: sensor choice by opening, EPA gauge stick and ATG rules, riser limits, vented cables and level-to-volume math.
How to measure sulfuric acid tank level: technology choice by concentration, radar antenna materials, SG 1.84 hydrostatic math and overfill protection.
How to meter steam condensate: flash steam math, a technology table with real temperature and conductivity limits, velocity sizing and energy accounting.
How HART puts digital data on a 4-20 mA loop, the 230 to 1100 ohm resistance window with the voltage budget worked out, PV to QV, and HART 5, 6 and 7.
Upstream is the side flow comes from, downstream is where it goes. Field checks for flow direction, the P1/P2 convention, and where instruments belong.
How to measure dew point: chilled mirror vs capacitive sensors, the Magnus formula worked through, pressure dew point, and the ISO 8573-1 humidity classes.
What wetted parts are, a media-to-material selection matrix, elastomer temperature windows, NACE and 3-A standards, and the six lines a wetted-parts RFQ needs.
What turndown ratio means, typical turndown by flow meter technology, the DP square-root penalty, and how transmitter turndown differs from meter turndown.
How Reynolds number decides flow meter selection: sourced Re limits for orifice, vortex and venturi, minimum-flow math, and what to use when flow goes laminar.
Convert differential pressure to flow with the square-root law: the ISO 5167 orifice equation, milliamp signal examples, and gas and steam density corrections.
Flow meter troubleshooting by symptom: zero readings, readings with no flow, offsets and unstable output on magnetic, vortex, turbine and Coriolis meters.
Troubleshoot a 4-20 mA pressure transmitter by loop current: fault bands, terminal voltage checks, zero and span drift limits, and when to repair or replace.
How to calibrate a pressure transmitter: five-point procedure, tolerance math in mA, as-found and as-left records, trim vs re-range, and calibration intervals.
Active vs passive 4-20 mA explained: who powers the loop, the multimeter test, 2, 3 and 4-wire mapping, what happens when two sources conflict, and the fixes.
How to install a pressure transmitter: tap orientation for liquid, gas and steam, impulse line slope, manifold valve sequence, loop wiring and zero trim.
What normally open and normally closed mean on a pressure switch, the four contact behaviors, fail-safe alarm wiring, deadband and how to test the contacts.
RTD vs thermocouple with real numbers: IEC 60751 and IEC 60584 tolerance classes, range limits, response times, drift, wiring cost and a selection table.
Split one 4-20 mA signal to two systems: splitter vs isolator, worked voltage budget math, sinking vs sourcing outputs, ground loops, HART and NE43 levels.
A flow meter reads rate; a flow totalizer integrates it into cumulative volume. Worked 4-20 mA and pulse K-factor math, P&ID tags, and accuracy of totals.
Calibration measures, adjustment changes the instrument, verification judges pass or fail. VIM definitions, an as-found and as-left example, and ISO 9001 rules.
How a BTU meter measures chilled water energy: the GPM x 500 x delta-T formula, ultrasonic vs magnetic meters, matched RTD pairs and glycol correction.
Choosing a water storage tank level sensor: NSF 61 and 372 for potable service, head and range math, pump deadband, and the five failures that matter.
How to choose a diesel tank level gauge or sensor: density and volume math, radar on low permittivity fuel, water bottoms, day tank alarms and dip checks.
What loop powered means on a 4-20 mA loop: the 3.5 mA current budget, voltage budget with a worked example, 2-wire vs 4-wire, and loop-powered indicator limits.
Flow meter calibration: gravimetric, prover and master meter methods, the 4:1 rule, K-factor correction with a worked example, and intervals by technology.
Compare 11 industrial flow meter types in one table: accuracy, sizes, turndown and straight run, plus selection criteria and a worked compressed air example.
Compare thermocouple types K, J, T, E, N, S, R and B: temperature ranges, IEC 60584 and ASTM E230 tolerance classes, wire color codes and a Type K mV table.
How 2, 3 and 4 wire RTD connections handle lead wire resistance, with error tables by wire gauge and cable length, IEC 60751 color codes and multimeter checks.
How to measure vacuum pressure: negative gauge vs absolute reference, unit conversions from torr to microns, and which instrument covers each vacuum range.
How a bourdon tube pressure gauge works: C-type, spiral and helical tubes, EN 837-1 accuracy classes, range selection and temperature error, worked numbers.
Percent of full scale is a fixed error set by the range; percent of reading scales with the reading. Conversion table, crossover formula, range sizing math.
Accuracy is closeness to the true value; precision is repeatability. Worked 0-10 bar transmitter example, ISO 5725 trueness, datasheet terms, class selection.
How to convert a 4-20 mA signal to 0-10 V, 1-5 V or 0-5 V: resistor values, why 500 ohm gives 2-10 V, loop compliance limits and NAMUR levels in volts.
Orifice plate tappings compared: corner, flange, and D and D/2 taps, with exact distances, how each changes the discharge coefficient, and which to choose.
How a venturi tube measures flow: the Bernoulli principle, ISO 5167-4 discharge coefficients, a worked sizing example, and when to choose one over an orifice.
Hydrostatic pressure is the weight of a liquid column: P = rho g h. Get the formula, a worked example, kPa and psi tables, and the transmitters that read it.
IP ratings explained for industrial instruments: what IP65, IP66, IP67 and IP68 mean, the full digit chart, a NEMA cross-reference, and the rating to specify.
Pressure drop formula step by step: Darcy-Weisbach equation, friction factor without a Moody chart, worked examples in kPa and psi, fittings and sizing rules.
Why gas and steam flow needs pressure and temperature compensation: formulas for DP and vortex meters, worked examples, steam rules and instrument choices.
How a U-tube manometer measures pressure: the rho g h formula, how to read both legs, fluid choice, inclined and well types, and when to use a DP transmitter.
Mass flow rate counts mass in kg/h; volumetric flow rate counts volume in m3/h. Conversion formula with worked numbers, density table, and meter selection.
How the IEC Zone system maps to the NEC Division system: Zone 0, 1, 2 definitions, gas groups IIA to IIC vs A to D, protection levels, and a marking decode.
Class 1 Div 1 means flammable gas during normal operation; Div 2 only under abnormal conditions. NEC definitions, gas groups, T-codes, and instrument selection.
Barometric pressure explained: 1013.25 hPa standard, a units conversion table, the three barometer types, and how an absolute pressure sensor reads the air.
Static, dynamic, and total pressure explained: the formulas, which pitot port reads which, a worked duct traverse, and the instrument that reads each one.
Flow meter K-factor explained: the pulses-per-volume formula, K-factor chart by meter type and size, worked Hz-to-GPM calculations, and field calibration steps.
A transducer gives a voltage output, a transmitter a 4-20 mA loop, a switch a contact at a setpoint. Compare all four devices and pick the right output.
Absolute pressure reads from a vacuum, gauge pressure from the atmosphere. Formula, worked examples, altitude table, and how to specify the right reference.
Pressure transducer wiring diagrams for 2-wire 4-20 mA loops, 3-wire voltage outputs, and 4-wire units, plus load resistance math, PLC hookup, and fault checks.
Flow rate units explained: GPM, L/min, L/s and m3/h with exact conversion factors, worked examples, gas standard-volume units, and datasheet sizing checks.
PSIA vs PSIG is about the zero point: gauge reads from atmosphere, absolute from a vacuum. See the table, the 14.7 psi conversion, PSID, and which to specify.
Flow meter straight run requirements by type: magnetic, turbine, vortex, orifice and Coriolis upstream/downstream diameters, a worked example, and ISO 5167.
Every industrial pressure unit defined: pascal, kPa, MPa, bar, psi, atm, kgf/cm2, torr and water column units, with NIST conversion factors and worked examples.
Compare 9 level transmitter types: radar, ultrasonic, guided wave, hydrostatic, DP, capacitance, magnetostrictive, float, plus a selection table by condition.
What a stilling well is, when radar and float transmitters need one, pipe sizing and hole-pattern tables, an installation checklist and common mistakes.
How a 4-20 mA current loop works: the live zero, scaling formulas with worked examples, loop power budget, NAMUR NE43 fault currents, and wiring distance.
Flow rate rises with the square root of differential pressure. Get the five key formulas, a worked orifice example, square-root scaling, and a free calculator.
How to select a cryogenic flow meter for LN₂, LOX, LNG and LH₂: technologies, Coriolis vs turbine, two-phase pitfalls, oxygen cleaning and a worked example.