What does free field mean?

Free-field measurement records a pressure wave travelling through the medium without reflecting off a wall, manifold, or pressure tap. The probe sits in the wave path on a slim support and the wave passes over a flush diaphragm, so what you measure is the incident wavefront, not a structure-modified version of it.

Why is the probe shaped like a teardrop?

The streamlined teardrop minimizes flow disturbance around the diaphragm. The slender 6.5 mm head paired with a 12 mm body and 406 mm trailing shaft lets the wavefront hit the diaphragm cleanly and the disturbance dissipate behind the probe.

Which CYG412 range should I pick?

Estimate the peak amplitude of your event, then pick the range whose full-scale value sits 30 to 50 percent above that peak. That gives headroom against shot-to-shot variability without sacrificing bridge sensitivity.

Do I need the anti-IR coating?

For far-field outdoor blast more than a few meters from the source, IR flash typically dissipates before reaching the diaphragm. For near-field detonation work or any test within direct line-of-sight of an open flame or explosive flash, specify the F4 anti-IR option.

How do I mount the CYG412 outdoors?

Use a ground stake or wave-aligned tripod, clamp on the M20×1.5 thread, and orient the 6.5 mm head toward the source within 15 degrees. Keep the cable run away from the line-of-sight.

When should I step up to CYG412 or CYG412?

Above 800 kPa peak amplitude, switch to the CYG412 (1 to 10 MPa). Above 10 MPa or for sub-microsecond rise time at high pressure, use CYG412 (20 to 100 MPa, 0.2 to 0.3 µs rise time).

CYG412 — Free-Field Dynamic Pressure Sensor

CYG412 High-Pressure Free-Field Sensor: Near-Field Detonation Measurement

Slim Φ8×405 mm teardrop probe for low-distortion wavefront capture in near-field high-energy detonation testing. 20 to 100 MPa range, 450–1000 kHz natural frequency, 0.2–0.3 µs rise time. Cavity-less flush diaphragm. Anti-IR optical option for near-field detonation environments.

100 MPa

Top of Range

1000 kHz

Natural Freq Peak

0.2 µs

Rise Time

Φ8 mm

Probe Head Diameter

Request a Quote View Range Table

CYG412 free-field pressure sensor — teardrop probe Φ8×405 mm for near-field detonation measurement

What a Free-Field Pressure Sensor Is

A free-field pressure sensor reads a pressure wave as it travels through air or water. Nothing bolts it to a wall, manifold, or pressure tap. The probe stands in the wave path, slim enough that the wave washes over the diaphragm instead of bouncing off a structure. Mount a sensor on a wall and you record the reflection and the wall’s ringing, not the incident wavefront the blast actually made.

The CYG412 is the high-pressure member of the CYG400 piezoresistive dynamic pressure family. Its probe is a streamlined teardrop, Φ8 mm across and 405 mm long. Two things keep distortion down. The body is slim enough that it barely disturbs the oncoming wave, and the diaphragm sits flush in a cavity-less mount, so there is no trapped cavity to ring and smear the rising edge.

Four ranges, 20 to 100 MPa, cover the high-amplitude end of blast work: near-field high-energy detonation, shaped-charge research, and internal-blast peak loading. If your event tops out below 20 MPa, drop to the CYG411 medium-pressure free-field; below 1 MPa, the CYG410 low-pressure free-field.

CYG412 Technical Specifications

Group	Parameter	Value
Sensing	Technology	MEMS piezoresistive silicon strain bridge
	Diaphragm	Stainless steel, fully flush, cavity-less
	Anti-light interference	Anti-IR optical coating (option F4)
Range & Speed	Range span	20 / 40 / 60 / 100 MPa
	Natural frequency	450 / 600 / 800 / 1000 kHz (range-matched)
	Rise time	0.3 µs (20–40 MPa); 0.2 µs (60–100 MPa)
Accuracy	Sensor accuracy	0.25% FS
	Non-linearity	±0.5% … ±1% FS
	Temperature drift	Zero 0.02 %FS/°C; sensitivity 0.03 %FS/°C
Power & Output	Power	1 mA / 15 mA constant current, or 12–24 VDC constant voltage
Power & Output	Output	Differential mV signal, or amplified ±5 V
Mechanical	Probe form	Streamlined teardrop, Φ8 mm probe × 405 mm length
	Mounting thread	M20×1.5
	Wetted material	Silicon + stainless steel; non-corrosive media
Environment	Operating temp	−40 to +85°C (silicone-oil fill); −55 to +125°C (special fill); to +200°C custom
Environment	Compensated temp	10 to 70°C

Range Selection: Four Models, One Probe Form

The CYG412 ships in four ranges. Probe, thread, and rise time stay the same across all of them; only the sensing element changes with range. Pick the one whose full scale sits about 30 to 50% above your expected peak. That leaves headroom without throwing away bridge sensitivity.

Range	Natural frequency	Rise time	Typical event
0–20 MPa	450 kHz	0.3 µs	Confined high-energy blast, near-field detonation
0–40 MPa	600 kHz	0.3 µs	Shaped-charge and close-in high-explosive research
0–60 MPa	800 kHz	0.2 µs	Strong reflected shock, internal-blast peak loading
0–100 MPa	1000 kHz	0.2 µs	Peak high-energy detonation, energetic-materials screening

At 60 and 100 MPa the natural frequency climbs to 800 and 1000 kHz and the rise time tightens to 0.2 µs, so even the fastest near-field transients still register on the rising edge. If your event peaks below 20 MPa, step down to the CYG411 medium-pressure free-field.

Where the CYG412 Is Used

The 20–100 MPa band is built for one job: near-field, high-energy detonation. Peak pressure runs into the tens of MPa, and the rising edge lands somewhere between a few tenths of a microsecond and a microsecond.

Outdoor Blast Wavefront

Near-to-mid-field detonation pressure profiles and free-air shockwave studies where the probe captures the incident wavefront at peak amplitudes of tens of MPa.

Shaped-Charge & Near-Field

Shaped-charge and close-in high-explosive characterization, where confined peak pressures reach 40–100 MPa over sub-microsecond rise times.

Structural-Loading Tests

Reflected-pressure on armor and hardened structures, internal-blast loading in test fixtures, and soil-shock studies from buried charges.

Shock-Tube Research

High-enthalpy and driver-section shock tubes in the MPa range — characterizing strong-shock profiles, reflected pressure, and gas-dynamic transients.

Ballistic-Gel & Medical

Near-field blast-injury research in ballistic gelatin or tissue surrogate, where transmitted peak pressure reaches the MPa range with sub-microsecond rise.

Energetic-Materials Screening

Propellant, pyrotechnic, and small-charge explosive characterization where peak output runs 20–100 MPa and the arena allows free-field probe placement.

Installation: Probe Orientation and Mounting

A free-field probe only reads cleanly if you orient and support it right. Three rules cover most outdoor blast setups.

Wave alignment. Point the Φ8 mm head at the source. The teardrop is shaped to take the wavefront square on the diaphragm with the shaft trailing behind, which keeps diffraction and reflection off the face. Past about 15° off-axis, peak amplitude starts to read low by an angle-dependent amount.

Mount support. Hold the probe at its M20×1.5 thread with a ground stake, a wave-aligned tripod, or a mast clamp. Never clamp the shaft. That gives the probe a bending mode and feeds mechanical ringing straight onto the rising edge. Route the cable clear of the line between probe and source.

Standoff distance. Set the probe at the radial distance you want to characterize, fix it precisely, and log it with the shot. In the near-to-mid field, pressure falls off steeply with distance, so a 10% error in standoff turns into a 20-30% error in pressure. The 405 mm shaft buys enough room to put the support well behind the head, out of the wave.

CYG412 Ordering Code

Standard order format:

CYG412 <range> <accuracy> <cable> <anti-IR> <custom>

Segment	Code	Meaning
Range	20 / 40 / 60 / 100	Full-scale value in MPa
Accuracy	P3 / P4	0.25% / 0.5% FS
Cable	C1 / CS	Direct lead / double-shielded twisted anti-interference cable (recommended outdoor)
Anti-IR	F4	Anti-IR optical coating (recommended for near-field detonation)
Custom	Q	Custom cable length, special temperature, or custom thread

Worked example: CYG412 60 P3 CS F4 Q — 0–60 MPa range, 0.25% accuracy, double-shielded outdoor cable, anti-IR optical coating, custom 25 m cable length per attached sheet.

CYG410 Low-Pressure Free-Field

300–800 kPa version of the same teardrop probe form. Step down for far-field blast and low-amplitude shock-tube work.

View product →

CYG411 Medium-Pressure Free-Field

1–10 MPa version with 0.5–1 µs rise time. Step down for confined medium-pressure blast and driver-tube shock.

View product →

CYG400 Series Overview

Full series guide covering all 10 models: cased, free-field, water-cooled, underwater, and composite probes. The selection map.

Read guide →

CYG412 FAQ

Free-field measurement captures a pressure wave as it moves through the medium, with nothing nearby for it to bounce off. The probe stands in the wave path on a slim support and the wave passes over a flush diaphragm, so you read the incident wavefront rather than a version reshaped by a wall or fitting.

The teardrop keeps flow disturbance around the diaphragm to a minimum. A blunt or stepped probe throws part of the wave back along its own body, and that reflection rings the rising edge. The slim Φ8 mm head and 405 mm trailing shaft let the wave reach the diaphragm clean and dissipate behind the probe.

Estimate your event’s peak, then choose the range whose full scale sits about 30 to 50% above it. That leaves headroom for shot-to-shot variation without giving up bridge sensitivity. When the peak straddles two ranges across a test matrix, oversize slightly rather than risk clipping.

In far-field blast, with the probe several meters out, the IR flash usually fades before it reaches the diaphragm. Up close, or any time the probe has direct line-of-sight to an open flame or detonation flash, add the F4 anti-IR option. Its chip-level optical coating stops the IR pulse before it can saturate the silicon junction and clip the rising edge.

Stake or tripod-mount it, clamp on the M20×1.5 thread rather than the shaft, and point the Φ8 mm head at the source within about 15°. Keep the cable out of the wave path and the line-of-sight so cable whip does not read back as noise on the rising edge.

Below 1 MPa peak, step down to the CYG410 (300–800 kPa). Between 1 and 10 MPa, use the CYG411 (1–10 MPa, 180–360 kHz). The CYG412 itself runs 20 to 100 MPa, 450–1000 kHz, 0.2–0.3 µs rise time, for near-field high-energy detonation. All three share a probe form and mount, so one fixture serves the whole free-field set.

Technical Support

Three background guides for engineers specifying or commissioning a CYG412 free-field probe. Open in a new tab; the deep-dives complement the spec-and-selection focus of this page.

Piezoresistive vs Capacitive Pressure Sensors

Decision framework for choosing between the two dominant MEMS sensing approaches — and why CYG412 piezoresistive wins for transient blast capture.

Read article →

Pressure Transducer Applications

Industry-by-industry guide to where pressure transducers fit, including the dynamic and shock-test contexts the CYG412 is designed for.

Read article →

Pressure Sensor Temperature Compensation

How temperature affects piezoresistive output and why the CYG412 ships with -40 to +85°C standard and -55 to +125°C extended ranges.

Read article →

Ready to Specify a CYG412?

Send us the expected peak amplitude, the radial distance to the source, the ambient temperature range, and whether near-field IR flash is in play. Our pressure-instrument engineers will reply with a CYG412 range, ordering code, and lead time.

Our engineers usually reply within 12 business hours.

Request a Quote Browse CYG400 Series

CYG412 High-Pressure Free-Field Sensor: Near-Field Detonation Measurement

What a Free-Field Pressure Sensor Is

CYG412 Technical Specifications

Range Selection: Four Models, One Probe Form