Crowcon T4 Calibration Service: Mail In Your Detector

Mail-in calibration for the Crowcon T4 costs $90 at CPS Calibrations — the published in-house rate for a 4- or 5-gas instrument — and covers every fitted channel as configured (oxygen, flammable gas/LEL, carbon monoxide, and hydrogen sulfide in the T4's 2-, 3-, and 4-gas builds), with as-found readings recorded before any adjustment, a sensor health check, and the detector returned with a certificate showing as-found and as-left data and a Certificate of Analysis link for each calibration gas bottle used. Ship it to 109 S. Front Street, Rockwood, TN 37854; call 865-900-8844 first to confirm the current turnaround.

The T4 is Crowcon's rugged personal 4-gas detector: drop-tested to 4 m onto concrete, IP65/IP67 sealing, a single button usable with gloves, up to 18 hours on its rechargeable Li-ion battery, and the traffic-light Positive Safety indicator supervisors read at a glance. Its verified channel ranges are oxygen 0–30% vol. (a long-life oxygen variant reads 0–25%), flammable 0–100% LEL, hydrogen sulfide 0–100 ppm, and carbon monoxide 0–1,000 ppm, including an H2-immune CO option. Configured, the Crowcon T4 runs $407.56–$872.51 across 14 builds — this post quotes the range, because the $755 headline figure is one configuration, not the line. Background reading: how to calibrate a Crowcon gas detector.

Crowcon T4 Portable Multi-Gas Detector

Rugged personal 4-gas detector for O2, LEL, CO and H2S — drop-tested to 4 m, up to 18 hours.

$407.56–$872.51 configured

See the T4

What a Mail-In T4 Calibration Covers

• Oxygen (O2), 0–30% vol. (long-life variant 0–25%) — as-found first; the channel that catches deficient and enriched air.
• Flammable gas, 0–100% LEL — spanned against documented gas, as-left recorded beside the rest.
• Carbon monoxide (CO), 0–1,000 ppm — including the H2-immune CO configuration, calibrated as the fitted sensor.
• Hydrogen sulfide (H2S), 0–100 ppm — the fast toxic channel, reported in its own units.

Two-, three-, and four-gas T4s all take the same bench discipline: the channels fitted are the channels calibrated, identified from the detector itself, each with as-found and as-left on one certificate.

T4x and MPS Notes — Read Before You Ship a Variant

Crowcon's T4 family includes the T4x, whose MPS-based flammable channel behaves differently from a catalytic LEL sensor — the MPS story (TrueLEL-style classification, poisoning immunity) is told in our fixed-monitor coverage, and the T4x has its own published spotlight and the T4 vs T4x comparison in the Learning Center. If your detector is a T4x rather than a catalytic T4, say so on the 865-900-8844 call: the work order should name the exact model and sensor set before the box leaves your dock, so the bench plans the right gases and checks.

The same applies to the H2-immune CO option and the long-life oxygen variant: configurations are calibrated as configured, and the certificate names what was actually in the detector.

Sensor Health, Repairs, and What Comes Back

Around the calibration sits the sensor health check — whether each channel is merely drifted or genuinely spent, sluggish, or unstable. A T4's TWA Resume feature keeps toxic exposure accounting honest across a shift even when the unit is switched off for a break; that honesty only means something if the sensors feeding it are verified, which is the bench's job. If a sensor fails, the next step is a written quote before any work. Approve it and the detector is repaired and calibrated; decline it and it returns as-is with its as-found record.

The certificate is the CPS standard, one tier: as-found and as-left for every fitted channel, plus a clickable CoA link for each calibration gas bottle used — the link stored when the bottle's supplier QR was scanned into service. The detector is tracked by serial number, and its record joins the CPS Calibration Program with a due-date reminder before the next calibration. Return shipping is the customer's cost. Send the detector and its charger (cradle versions included); include company, contact, and serial number. Do not send calibration gas. The general process: how mail-in gas detector calibration works.

Frequently Asked Questions

How much does it cost to calibrate a Crowcon T4?

$90 at CPS Calibrations — the published in-house rate for 4- and 5-gas instruments, bench work at our Rockwood, Tennessee shop. It never applies to on-site work. Shipping is separate both ways; repairs beyond calibration are quoted in writing first.

What does T4 calibration include?

Every fitted channel calibrated as configured — O2, LEL, CO, H2S in the detector's 2-, 3-, or 4-gas build — with as-found readings recorded before adjustment, as-left readings after, a sensor health check, and a full certificate with a Certificate of Analysis link for each gas bottle used, plus enrollment in the CPS Calibration Program.

My T4 is a 2-gas or 3-gas build — is it still $90?

Yes. The rate follows the instrument class — multi-gas in-house calibration is $90 — and the bench calibrates the channels fitted, whether that is two, three, or four. The certificate names exactly the channels your build carries.

Can you calibrate the T4x with the MPS sensor?

Tell us it is a T4x when you call 865-900-8844. The MPS flammable channel is a different sensor technology from the catalytic T4, and the work order will name the exact model and sensor set so the bench plans correctly. The T4 vs T4x comparison and the T4x spotlight in our Learning Center cover the differences.

What is the H2-immune CO option, and does it change calibration?

It is a carbon monoxide configuration (0–1,000 ppm) built to resist hydrogen cross-interference. Calibration still spans the CO channel against documented CO gas as configured — what the option changes is the sensor's behavior around hydrogen in the field, and the certificate identifies the fitted configuration.

What happens if a T4 sensor fails calibration?

The as-found data and health check identify the channel; anything beyond calibration is quoted in writing for your approval before work begins. Decline the quote and the detector returns as-is with its as-found record documenting where it stands.

How long will my T4 be gone?

Call 865-900-8844 before shipping for the current bench turnaround — we do not publish a fixed figure, because it honestly depends on the queue and on any sensor decision waiting on you. Transit both ways is the carrier's time. The $90 rate is fixed.

What does a new T4 cost if mine is beyond repair?

$407.56–$872.51 configured across 14 builds — gas count, the long-life O2 and H2-immune CO options, and cradle (CRD) versions set the price. Most failed T4s need a sensor, not a replacement, and the written repair quote arrives before that decision is due.

Should I send the charging cradle with my T4?

Send the detector and the charger or cradle your version uses (versions suffixed CRD include the charging cradle), plus a note with company name, contact, and serial number. Do not send calibration gas — CPS calibrates with its own documented gas.

Where do I ship my T4?

CPS Calibrations, 109 S. Front Street, Rockwood, TN 37854, after calling 865-900-8844 to confirm turnaround and note your configuration (standard T4 or T4x, gas build, any H2-immune or long-life-O2 options).

The Bottom Line

A T4 is carried into the worst air on site — its calibration should be the least doubtful thing about it. Mail yours to CPS and for the published $90 in-house rate every fitted channel is calibrated as configured, as-found first, health-checked, and returned with the full certificate and CoA trail. Ready to mail your T4 in? Call 865-900-8844, then ship it to 109 S. Front Street, Rockwood, TN 37854.

New to the T4 itself? Start with our overview: Crowcon T4: what it detects, what it costs, and who it's for — sensors, ranges, configurations and US pricing.