Industrial Measurement Instruments: Selection & Buying Guide (2026)

What Are Industrial Measurement Instruments?

Measurement instruments sense a physical variable — pressure, temperature, humidity, or electrical current — and either display it locally or transmit a standardised signal to a control system. In industrial plant environments, accurate measurement underpins safe operation, energy efficiency, and regulatory compliance. The 3G Electric catalogue carries 733 measurement products spanning four leading OEM brands: Dwyer (379 SKUs), Preciman (196 SKUs), CBM (24 SKUs), and Grundfos (1 SKU).

Main Instrument Types in This Category

Differential Pressure Gauges

Dwyer's iconic Magnehelic Series 2000 gauges use a frictionless, helix-free diaphragm mechanism to indicate differential pressure without electrical power. The 2000-60PA (SKU DWY01202) covers 0–60 Pa with ±1% accuracy, a 101.6 mm (4 inch) dial, and 1/8" female NPT pressure connections. The 2000-4KPA (SKU DWY01408) extends the range to 4 kPa and complies with EU Directive 2014/68/EU (PED). Both operate between -6.67 and 60°C with diaphragm-vertical mounting. The Series 2300 variants (SKUs DWY01202, DWY01602, DWY01608) offer the same platform in 60 Pa and 120 Pa ranges for low-pressure HVAC and cleanroom monitoring.

Differential Pressure Transmitters

Where remote monitoring or BMS integration is required, electronic transmitters output a 4–20 mA or 0–10 V signal. The 629-05-CH-P2-E5-S1-3V (SKU DWY06016) covers 0–100 psid with 0.5% accuracy, IP65 enclosure, CE certification, and a burst pressure of 500 psi. The 629-04-CH-P2-E5-S1-3V (SKU DWY06014) is the 0–50 psid sibling, rated to 100 psi overpressure, suited to liquid differential measurement via 1/4" NPT female process connections. For low-pressure air and gas applications, the 616K-11-TC and 616K-14-TC (SKUs DWY04204, DWY04210) transmit 0–250 Pa via 4–20 mA or 0–10 V with barbed dual-size tubing connections (3 mm and 5 mm) and screw-terminal electrical connections.

Temperature Sensors and Probes

Temperature measurement products in this catalogue include wall-mounted probes, surface probes, and immersion thermowells. The TE-END-F wall probe (SKU DWY40024) and TE-NND-D (SKU DWY40008) both use 10 kΩ thermistors and ABS housings rated -40 to +60°C. The S2-1C surface probe (SKU DWY48012) features a 25 mm stainless steel 304 probe, 6.3 mm diameter, 584.2 mm lead wire (22 AWG), and dual accuracy ratings: ±0.5°F at 21.1°C (RTD nickel) and ±0.2°C at 25°C (thermistor). The TE-TNS-N083N-00 thermowell (SKU DWY44008) is a 10 kΩ Type III immersion sensor with a 20 cm insertion length, 1/2" NPT process connection, and UL94 V-0 polycarbonate housing.

Temperature and Humidity Combination Probes

The WHT-322 (SKU DWY12008) combines a 10 kΩ thermistor (Dwyer Curve A) with a humidity sensor in a NEMA 3S (IP54) ABS housing. It outputs 0–10 VDC, covers -20 to +60°C (-4 to +140°F), and achieves ±3% humidity accuracy — suitable for HVAC air-handling units and building automation systems.

Current Transmitters

The CCT 70-100 (SKU DWY60608) from Dwyer's CCT40/50 series measures RMS current via a solid or split-core configuration with a site-configurable range — useful for motor load monitoring and energy sub-metering without interrupting the circuit.

Static Pressure Taps

The A-491 stainless static pressure tap (SKU DWY80012) provides a clean pressure sensing point in ductwork or pipework. The probe is stainless steel 304, the flange stainless 430, and the fitting stainless 303, with a barbed connection for 3/16" ID tubing. Available in 101 mm, 152 mm, and 203 mm insertion lengths to suit different duct sizes.

Instrument Selection Criteria

• Measurement range: Select a range where your normal operating point sits at 60–80% of full scale to preserve accuracy and avoid overpressure trips.
• Output type: Local-read applications use analogue gauges; BMS/SCADA integration requires 4–20 mA or 0–10 VDC transmitters.
• Accuracy class: Check the stamped or datasheet accuracy figure (e.g. ±1% FS on the Magnehelic 2000-60PA, ±0.5% on the 629-series transmitters).
• Process connection: Match thread standard (NPT, BSP) and size to existing pipework or ductwork tappings.
• Enclosure rating: IP65 (629-series) for wet or washdown areas; IP54 (WHT-322) for indoor HVAC; IP10 (616K-series) for protected panel mounting only.
• Operating temperature: Most probes listed are rated to -40°C minimum and +60°C maximum — verify suitability for high-temperature process lines.
• Overpressure / burst rating: The 629-05 transmitter withstands 500 psi burst; the 629-04 is rated to 100 psi overpressure. Always confirm these exceed your worst-case surge pressure.
• Certification requirements: Check whether CE, PED (EU Directive 2014/68/EU), or other regional approvals are mandatory for your installation.

Specification Comparison Table

How to Specify and Order the Right Instrument

1. Define the measured variable: Confirm whether you need pressure (differential or gauge), temperature, humidity, or current measurement.
2. Establish the operating range: Identify normal operating values and maximum surge values. Choose a full-scale range where normal operation sits at approximately 60–80% of span.
3. Select output format: Decide between local indication (Magnehelic dial gauges) and electronic output (4–20 mA or 0–10 VDC transmitters) based on your control system requirements.
4. Confirm process connection: Note thread type (NPT vs. BSP), size, and whether barbed tubing fittings or flanged connections are needed. Check insertion length for immersion sensors.
5. Check environmental ratings: Match IP rating to installation environment — IP65 minimum for outdoor or washdown zones.
6. Verify certifications: Confirm CE, PED, or other regional approvals required by your local authority or insurance underwriter.
7. Request a quotation: Submit the SKU or model number to 3G Electric. Lead time is confirmed at quotation stage; all products are available to order with global logistics and customs handling.

Leading OEM Brands

Dwyer Instruments dominates this catalogue with 379 SKUs covering the full measurement spectrum — Magnehelic gauges, 600-series transmitters, thermistors, thermowells, humidity probes, and current transmitters. Preciman contributes 196 SKUs, while CBM adds 24 specialised measurement products. Grundfos appears with one measurement SKU, reflecting its primary strength in pump systems with integrated sensing. When specifying Dwyer products, always cross-reference the model suffix (e.g. -CH-P2-E5-S1-3V on the 629-series) against the Dwyer configuration guide, as each character encodes a specific option.

Frequently Asked Questions

What is the difference between a Magnehelic gauge and a differential pressure transmitter?

A Magnehelic gauge (e.g. Dwyer Series 2000) provides local visual indication with no electrical power required. A differential pressure transmitter (e.g. Dwyer 629-series) outputs a 4–20 mA or 0–10 VDC signal for remote monitoring or BMS integration. Choose a gauge for simple local checks; choose a transmitter when data logging or automated control is needed.

What does IP65 mean on a pressure transmitter?

IP65 means the enclosure is fully dust-tight (6) and protected against low-pressure water jets from any direction (5). The Dwyer 629-04 and 629-05 transmitters carry IP65 ratings, making them suitable for outdoor installations or areas subject to washdown, unlike the IP10-rated 616K-series which requires protected indoor mounting.

How do I select the correct insertion length for an immersion temperature sensor?

The insertion length must reach the centre of the pipe or duct flow stream. For the Dwyer TE-TNS-N083N-00 thermowell (20 cm insertion, 1/2" NPT), measure the pipe diameter and wall thickness, then confirm the probe tip will sit at mid-flow. Consult the sensor datasheet for minimum immersion depth requirements.

Can the CCT 70-100 current transmitter be installed without interrupting the circuit?

Yes. The CCT 70-100 (SKU DWY60608) offers a split-core configuration that clamps around an existing conductor without breaking the circuit. The solid-core option is used during new installations. The measurement range is site-configurable, so confirm the expected current range before installation.

What tubing size does the A-491 static pressure tap require?

The Dwyer A-491 (SKU DWY80012) uses a barbed fitting designed for 3/16" (approximately 4.8 mm) internal diameter tubing. It is available in three insertion lengths — 101 mm, 152 mm, and 203 mm — to suit different duct wall thicknesses and flow profiles.

Are Dwyer Magnehelic gauges compliant with European pressure equipment regulations?

The Dwyer 2000-4KPA (SKU DWY01408) is explicitly listed as complying with EU Directive 2014/68/EU (Pressure Equipment Directive). For other Magnehelic models, request the Declaration of Conformity at quotation stage to confirm applicable certifications for your installation country.

How many measurement SKUs does 3G Electric carry?

The 3G Electric measurement catalogue contains 733 SKUs across Dwyer (379 SKUs), Preciman (196 SKUs), CBM (24 SKUs), and Grundfos (1 SKU). All products are available to order; lead time is confirmed at quotation. Contact 3G Electric with your model number or application requirements for a tailored recommendation.

What accuracy should I expect from a thermistor-based temperature probe?

The Dwyer S2-1C surface probe (SKU DWY48012) achieves ±0.2°C at 25°C in thermistor mode. Wall probes such as the TE-END-F and TE-NND-D use 10 kΩ Type II/III thermistors; check their individual datasheets for accuracy figures, as values vary with temperature across the operating range of -40 to +60°C.