Testo 340 - Multigas Combustion Engine Tuning Analyzer
Source Monitoring
Testo 340 - Multigas Combustion Engine Tuning Analyzer
The Testo 340 by Testo is a portable, handheld flue gas analyzer designed for combustion tuning and maintenance of engines, boilers, furnaces, and process heating equipment. It measures up to four gases simultaneously — O₂ (0–25% vol.), CO (0–10,000 ppm), NO (0–3,000 ppm), and NO₂ (0–500 ppm) — with automatic combustion efficiency and excess air calculations displayed in real time. CO₂ is calculated from the measured O₂. On-board data storage and Bluetooth transfer to Testo's easyEmission software support on-site documentation, making it well-suited for mechanical engineers and facility maintenance teams performing routine combustion tuning and preventative maintenance on commercial heating equipment.
Choose Your Option
Rent for flexible short-term use or purchase to own
Rental Rates
Daily
$225.00
Weekly
$645.00
Monthly
Contact for pricing
Reference rates only. You get the best rate calculation - actual price based on your selected rental dates.
What is the Testo 340 used for?
It's a portable multi-gas combustion analyzer for tuning and troubleshooting boilers, furnaces, and engines. It measures up to four gases simultaneously — O₂, CO, NO, NO₂, and SO₂ — and automatically calculates combustion efficiency and excess air, giving you the numbers needed to adjust air-to-fuel ratio and document performance.
Testo 340 vs. Testo 350 — which do I need?
Use the Testo 340 for routine combustion tuning, efficiency testing, and basic emissions measurements when up to four gases is sufficient. Use the Testo 350 when your test plan requires more gases (including hydrocarbons), compliance-grade documentation, or formal regulatory reporting. For everyday boiler and furnace work, the 340 covers most use cases.
What measurement ranges does the Testo 340 cover?
O₂ 0–25% vol, CO 0–10,000 ppm (low range: 0–500 ppm), NO 0–3,000 ppm (low range: 0–300 ppm), NO₂ 0–5,000 ppm, SO₂ 0–5,000 ppm. Confirm which sensors are installed for your rental if your application requires a specific gas or low-range resolution.
What does excess air tell me, and why does it matter for tuning?
Excess air is the air supplied beyond what combustion chemically requires. Too much reduces efficiency; too little increases CO and combustion byproducts. The Testo 340 reports excess air alongside efficiency calculations so you can tune toward the right balance — always within equipment manufacturer guidelines and site safety requirements.
How do I take a proper flue gas reading?
Insert the sampling probe into a stable, representative flue gas stream. Let readings fully stabilize before recording — don't capture numbers while the display is still settling. Keep probe placement consistent when comparing before/after adjustments. Check for condensation or particulate loading in the sampling path if readings seem erratic.
Does the Testo 340 datalog results?
Yes. Datalogging creates a time-stamped record across tuning sessions or multiple assets. Confirm your reporting format — exported logs, printed tickets, or manual transcription — before you start fieldwork so you're not re-running tests to meet documentation requirements.
What's included in the rental kit?
The kit includes the Testo 340 analyzer with up to four gas sensors, flue gas sampling probe with thermocouple, integrated printer with paper, rechargeable battery, AC charger, protective carrying case, calibration certificates, and instruction manual. Confirm sensor configuration before dispatch if your work requires a specific gas.
What does it cost to rent the Testo 340?
$225/day and $645/week. Pricing beyond two weeks is by quote. For boiler or furnace tuning campaigns, total cost is driven by the number of assets and test points — the day rate is fixed, but multi-asset projects benefit from a weekly or quoted rate.
Exposure Hazards This Equipment Detects
Oxygen (O₂)
CAS:
7782-44-7
Learn More
Updated on March 09, 2026
PEL TWA
N/A
REL TWA
N/A
TLV TWA
N/A
Nitrogen Dioxide (NO₂)
CAS:
10102-44-0
Learn More
Updated on October 08, 2026
PEL TWA
N/A
REL TWA
N/A
TLV TWA
0.2 ppm (0.38 mg/m³)
Carbon Monoxide (CO)
CAS:
630-08-0
Learn More
Updated on October 08, 2026
PEL TWA
50 ppm (55 mg/m³)
REL TWA
35 ppm (40 mg/m³)
TLV TWA
25 ppm (29 mg/m³)
Nitric Oxide (NO)
CAS:
10102-43-9
Learn More
Updated on October 08, 2026
PEL TWA
25 ppm (30 mg/m³)
REL TWA
25 ppm (30 mg/m³)
TLV TWA
25 ppm [1992]
Features & Capabilities
| Datalogging: | ✓ Yes |
| Monitoring Scope: | Source Monitoring |
Equipment Specifications
| Detection Method / Sensor Type: | O2: Electrochemical. CO: Electrochemical (H2 compensated). NO: Electrochemical. NO2: Electrochemical |
| Calculated Parameters: | Combustion efficiency (0–120%); Flue gas loss (0–99.9% qA); CO₂ (calculated from O₂, ±0.2% vol); Flue gas dewpoint (0–211°F) |
| Gas Channels: | O₂: 0–25% vol; ±0.2% vol; resolution 0.01% vol; response 20s (t90), CO (H₂ compensated): 0–10,000 ppm; ±10 ppm or ±10% (0–200 ppm), ±20 ppm or ±5% (201–2,000 ppm), ±10% (2,001–10,000 ppm); resolution 1 ppm; response 40s (t90), CO Low Range (optional sensor, H₂ compensated): 0–500 ppm; ±3 ppm (0–39.9 ppm), ±5% (remaining range); resolution 0.1 ppm; response 40s (t90), NO: 0–3,000 ppm; ±5 ppm (0–99 ppm), ±5% (100–1,999 ppm), ±10% (2,000–3,000 ppm); resolution 1 ppm; response 30s (t90), NO Low Range (optional sensor): 0–300 ppm; ±3 ppm (0–39.9 ppm), ±5% (remaining range); resolution 0.1 ppm; response 30s (t90), NO₂: 0–500 ppm; ±10 ppm (0–199 ppm), ±5% (remaining range); resolution 0.1 ppm; response 40s (t90) |
| Sample Flow Rate: | Built-in pump, 1.0 L/min; hose length up to 25 ft |
| Additional Measurements: | Draft pressure: -16 to 16 in H₂O; Differential pressure: -80 to 80 in H₂O; Absolute pressure: -240 to 461.5 in H₂O; Flue gas temperature (Type K, NiCr-Ni): -40 to 2,192°F |
| Bluetooth: | ✓ Yes |
| Protection Class: | IP40 |
| Data Logging Interval: | 5 user-defined onboard logging programs; easyEmission PC software supports 1 sec–1 hr logging intervals. Testo states a single measurement should not run longer than 2 hours, to avoid drift |
| Data Storage Capacity: | Up to 100 folders × 10 sites per folder × 200 logs per site |
| Battery Run Time: | Over 6 hours with pump on (display light off, 68°F); Li-ion 3.7V/2.4Ah; AC power supply available (6.3V/2A) |
Kit Contents
Manufacturer Resources
Documents
User manuals, safety guides, and technical documentation from the manufacturer:
- Testo 340 Specs PDF
- Testo 340 Manual PDF
- Testo 340: What's in the box PDF
- Practical Guide: Industrial Flue Gas Analysis PDF
Videos
No manufacturer videos are currently available for this product. Check back later or contact us for more information.
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Rental Dates Notice