{"product_id":"testo-co-replacement-sensor-low-0390-0078","title":"Testo CO Replacement Sensor (Low Range)","description":"\u003cdiv style=\"text-align: left;\"\u003e\n\u003cp style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eThis Testo 0390 0078 CO replacement sensor is built for keeping your combustion analyser sharp, helping HVAC and plumbing techs maintain accurate readings on gas appliances. In Australia, checking for CO is critical for safety and compliance, especially with flued heaters and boilers.\u003c\/p\u003e\n\u003cp style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eAfter a few years of hard work, or if you've had a particularly rough run with dirty flues, these sensors can drift. Swapping it out ensures your analyser is giving you trustworthy numbers, vital for protecting occupants and avoiding re-work.\u003c\/p\u003e\n\u003ch2 style=\"color: #007acc; border-bottom: 2px solid #f0f0f0; padding-bottom: 8px; margin-top: 35px;\"\u003eBest For\u003c\/h2\u003e\n\u003cul style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eRoutine maintenance and servicing of Testo combustion analysers.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eReplacing faulty or aged CO sensors in compatible units.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eEnsuring accurate CO measurements during gas appliance commissioning and safety checks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 style=\"color: #007acc; border-bottom: 2px solid #f0f0f0; padding-bottom: 8px; margin-top: 35px;\"\u003eCompatibility\u003c\/h2\u003e\n\u003cp style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eDesigned as a direct replacement for compatible Testo combustion analysers. Features H2 compensation, making it suitable for a range of gas types where hydrogen might be present. If you're running a different model, check fittings and specs before ordering.\u003c\/p\u003e\n\u003ch2 style=\"color: #007acc; border-bottom: 2px solid #f0f0f0; padding-bottom: 8px; margin-top: 35px;\"\u003eFeatures\u003c\/h2\u003e\n\u003cul style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cstrong\u003e0-500 ppm CO Range:\u003c\/strong\u003e Accurately measures low to moderate levels of carbon monoxide.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cstrong\u003e0.1 ppm Resolution:\u003c\/strong\u003e Provides fine detection for precise readings.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cstrong\u003eH2 Compensated:\u003c\/strong\u003e Reduces interference from hydrogen, improving measurement accuracy in various gas mixtures.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cstrong\u003eGenuine Testo Part:\u003c\/strong\u003e Ensures optimal performance and full compatibility with your Testo analyser.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 style=\"color: #007acc; border-bottom: 2px solid #f0f0f0; padding-bottom: 8px; margin-top: 35px;\"\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 16px; margin-bottom: 20px;\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth style=\"color: #007acc; border: 1px solid #e0e0e0; padding: 10px; text-align: left; background-color: #f5f5f5;\"\u003eParameter\u003c\/th\u003e\n\u003cth style=\"color: #007acc; border: 1px solid #e0e0e0; padding: 10px; text-align: left; background-color: #f5f5f5;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px;\"\u003eMeasurement Range\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px;\"\u003e0 to 500 ppm CO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px;\"\u003eResolution\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px;\"\u003e0.1 ppm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px;\"\u003eCompensation\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px;\"\u003eH2 compensated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px;\"\u003ePart Number\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px;\"\u003e0390 0078\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2 style=\"color: #007acc; border-bottom: 2px solid #f0f0f0; padding-bottom: 8px; margin-top: 35px;\"\u003eWhat's in the Box\u003c\/h2\u003e\n\u003cul style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e1x Testo 0390 0078 CO Replacement Sensor, Low\u003c\/li\u003e\u003c\/ul\u003e\n\u003ch2 style=\"color: #007acc; border-bottom: 2px solid #f0f0f0; padding-bottom: 8px; margin-top: 35px;\"\u003eUsing It on the Job\u003c\/h2\u003e\n\u003col style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cstrong\u003ePower Down:\u003c\/strong\u003e Safely power down and isolate your Testo combustion analyser before proceeding.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cstrong\u003eConsult Manual:\u003c\/strong\u003e Refer to your specific analyser's instruction manual for detailed sensor replacement steps and any specific precautions.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cstrong\u003eReplace Sensor:\u003c\/strong\u003e Carefully remove the old CO sensor and install the new 0390 0078, ensuring correct orientation and a secure connection. Avoid touching the sensor surface directly.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cstrong\u003eCalibrate\/Zero:\u003c\/strong\u003e Power up the analyser and perform any required calibration, zeroing, or fresh air adjustment procedure as per the manufacturer's guide. This step is critical for accuracy.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cstrong\u003eVerify Operation:\u003c\/strong\u003e Always test the analyser with a known CO source or in fresh air before relying on readings for critical safety checks on appliances.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003ch2 style=\"color: #007acc; border-bottom: 2px solid #f0f0f0; padding-bottom: 8px; margin-top: 35px;\"\u003eLimitations \u0026amp; Safety Notes\u003c\/h2\u003e\n\u003cul style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eRequires installation into a compatible Testo combustion analyser model. Verify compatibility before purchase.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eDo not attempt to open, repair, or modify the sensor itself.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eAlways follow the safety guidelines and service instructions provided in your Testo analyser's user manual.\u003c\/li\u003e\n\u003cli style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eProper calibration after replacement is essential to maintain measurement accuracy and ensure reliable operation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cblockquote style=\"border-left: 4px solid #007acc; background-color: #f9f9f9; font-style: italic; padding: 15px; margin: 20px 0;\"\u003e\u003cp style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003eTradie Pro Tip: Keep a spare sensor on the truck, especially if your analyser is getting a bit old or sees a lot of use. Nothing worse than pulling up to a job, doing a pre-check, and finding your CO sensor is out of whack – it saves a return trip and keeps you efficient.\u003c\/p\u003e\u003c\/blockquote\u003e\n\u003ch2 style=\"color: #007acc; border-bottom: 2px solid #f0f0f0; padding-bottom: 8px; margin-top: 35px;\"\u003ePair With\u003c\/h2\u003e\n\u003cp style=\"font-size: 16px; line-height: 1.6; margin-bottom: 20px;\"\u003ePair with Testo combustion analysers, calibration gases, and flue gas probes for a complete combustion analysis toolkit. Ensure your analyser is regularly serviced to maintain peak performance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!-- Automated FAQ Schema --\u003e\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the CO measurement range and resolution of this sensor?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The Testo 0390 0078 sensor measures Carbon Monoxide (CO) from 0 to 500 ppm. It provides a fine resolution of 0.1 ppm, allowing for precise detection of CO levels.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is this sensor compatible with all Testo analysers?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This sensor is designed as a direct replacement for compatible Testo combustion analysers. You should refer to your specific analyser's manual to confirm compatibility with part number 0390 0078.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do I need to calibrate my analyser after replacing the CO sensor?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes, after installing the new sensor, it is critical to perform the necessary calibration, zeroing, or fresh air adjustment procedure as outlined in your Testo analyser's user manual to ensure accurate and reliable operation.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"Testo","offers":[{"title":"Default Title","offer_id":43785702506555,"sku":"0390 0078","price":1996.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0316\/7787\/4235\/files\/xtesto-0390-0078-co-replacement-sensor.jpg.pagespeed.ic.x43qBEZbOq.jpg?v=1784012963","url":"https:\/\/www.hvacshop.com.au\/products\/testo-co-replacement-sensor-low-0390-0078","provider":"HVAC Supply Shop","version":"1.0","type":"link"}