Oehler Research · Ballistic Chronographs
Oehler Model 35P
Often called the gold standard of ballistic chronographs: two independent velocity readings on every shot, checked against each other automatically.
The Model 35P is for people who need to know not only what a velocity was, but whether that number can be trusted. Most chronographs report a single figure, and the operator has no way to tell if light, vibration or a false trigger corrupted it. The 35P uses three Skyscreen III screens with two timers, so every shot yields two independent velocities. The patented PROOF CHANNEL circuit compares them and flags any pair that disagrees beyond a reasonable tolerance, so a plausible but wrong reading cannot slip into the record. Typical accuracy is 0.25% on the 4 ft rail supplied with the unit. The built-in printer uses real ink on plain paper, not thermal stock, so the record prints on the spot and does not fade in storage. It handles archery, airguns, handguns, shotguns and rifles.
Overview
The Model 35P is built to industrial standards and has been used by government laboratories and the ammunition industry for decades. The measurement uses three Skyscreen III sky-lit screens and two timers: screens one and two form one baseline, screens two and three form a second, and each is timed and converted to velocity on its own. PROOF CHANNEL compares the two results and warns immediately when they differ by more than a reasonable amount, so the operator knows that shot is suspect instead of letting it contaminate the statistics. Typical accuracy is 0.25% when the screens sit on the supplied 4 ft rail. The rail carries dimples that fix the spacing of the three screens, and that matters because spacing is the denominator of the velocity calculation: any setup error goes straight into the result. Skyscreen III uses an improved diffuser and folding stands, triggers reliably in low light, and works across a wide temperature range, which suits outdoor ranges and field testing. Beyond shot-by-shot velocity the unit also reports the mean and the uniformity of the string. Evencat supplies and quotes the Model 35P in Taiwan.

Key specifications
| Typical accuracy | 0.25% with the 4 ft rail |
|---|---|
| Measurement layout | Three Skyscreen III screens + two timers, two independent velocities per shot |
| PROOF CHANNEL | Compares both readings automatically and flags any disagreement beyond tolerance |
| Output | Built-in printer, real ink on plain paper (not thermal) |
| Statistics | Mean velocity and uniformity |
| Suitable for | Archery, airguns, handguns, shotguns, rifles |
Features
PROOF CHANNEL dual-reading check
Two independent readings per shot are cross-checked automatically, so plausible but wrong data never reaches the statistics.
Plain-paper printing that does not fade
Real ink on ordinary paper instead of thermal stock: print on the spot and archive the record for years.
Reliable triggering in low light
Skyscreen III's improved diffuser and folding stands keep it working on overcast days, at dawn and at dusk.
Wide operating temperature
Suited to outdoor ranges and field testing; no climate-controlled room needed.
Mean and uniformity statistics
Batch consistency figures alongside the shot data, directly supporting load verification.
Operation and applications

RECORD · PRINT
Print on plain paper, file it at once
The built-in printer uses real ink on ordinary paper, so the record can be filed straight from the range and does not fade like thermal paper.
SENSORS · SCREENS
Three Skyscreen III units form two baselines
Screens one and two, then two and three, each form a baseline; timing them independently is what makes PROOF CHANNEL possible.


RANGE MEASUREMENT · RANGE
Ranges and proving grounds
Muzzle velocity, time of flight and impact measurement outdoors call for sensors that survive sun, dust and muzzle blast, plus a controller that runs for hours on its own power.
R&D
Development and load verification
Comparing loads, bullet shapes and barrel conditions only works when the measurement system's own uncertainty is far smaller than the differences under test.

Options and configuration
Tick the items you need and we will compile the configuration into the inquiry form. Oehler products are quoted case by case by the manufacturer; lead time is as confirmed by Oehler.
Standard equipment (included)
Options and add-ons
Service and support
Downloads
Evencat supplies and quotes Oehler Research, Inc. (Austin, Texas, USA) products in Taiwan, and provides selection advice, supply assessment and training.
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