Product Introduction
The FNIRSI SG-004A Multifunctional Signal Generator is a compact yet powerful process calibrator designed to address the complex needs of industrial automation, electrical engineering, and DIY electronics. This device stands out in the market by offering an extensive range of signal generation and measurement capabilities, including current, voltage, frequency, resistance, and a comprehensive suite of thermocouple types. It serves as an indispensable tool for calibrating pressure transmitters, PLC systems, and various process instruments, ensuring precise control and accurate readings in critical applications. Its mini size, combined with a backlit screen and rapid 1-second result display, makes it uniquely portable and efficient for field use, empowering professionals and enthusiasts alike to troubleshoot, test, and maintain complex electrical systems with unparalleled ease and accuracy. Check out our other technical reviews for more hardware testing.

Hardware specifications
Core Specifications: FNIRSI SG-004A
Available Versions
Available Versions & Selection Guide
The FNIRSI SG-004A is available in two color variants: SG-004A-BU (Blue) and SG-004A-YE (Yellow). Both versions offer the same robust functionality and user-friendly interface, designed for intuitive operation by electrical DIY enthusiasts. The device features Digital Signal Processing and covers a wide temperature range, from TC(TC-N) at 0-1290℃ up to TC(WRe5/26) at 0-2320℃, accommodating diverse temperature calibration requirements. It provides versatile signal output, supporting Millivolt (mV), Current (mA), and Passive(XMT) signals for compatibility with various devices. Comprehensive thermocouple support is a key feature, including TC(TC-N), TC(TC-J), TC(TC-K), TC(TC-E), TC(TC-S), TC(WRe3/25), and TC(WRe5/26) types for extensive temperature calibration. Furthermore, it boasts high frequency capability, generating signals up to 9999Hz with FRQ(Hz), which is ideal for precise frequency testing in electrical systems.
Package Contents
What’s in the Box?
- The FNIRSI SG-004A comes with a comprehensive set of accessories to ensure immediate usability and versatility. The package includes four Alligator Test Clips, one USB charger, the SG-004A Signal Generator unit itself, one User Manual for detailed operation instructions, one Type-C Cable for charging and data transfer, and a protective Packing Box.
Features and benefits
Why I love FNIRSI SG-004A
Pros and Cons
Strengths & Weaknesses:
What I Like
Points to Consider
Price and Availability
Where to Buy & Customer Reviews
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Store info
STORE
⭐ 98.6% Positive Feedback | 123.0K Followers
| Name: | FNIRSI Official Store |
| Store no.: | 2939001 |
| Location: | China |
| Open since: | Feb 26, 2017 |
Detailed seller ratings
| Item as Described | 4.9 Above Average |
| Communication | 4.9 Above Average |
| Shipping Speed | 4.9 Above Average |
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User reviews
User Reviews & Feedback Analysis ⭐ 4.6 (22) | Sold (569)
Reviews FNIRSI SG-004A
Authentic Feedback Analysis:
⭐ 5/5 | AliExpress Shopper: Material received on time, parcel tracking worked well, very satisfied. I used the SG-004A 4-20mA to adjust a 4-20mA to 0-3.3V conversion board and explored the device’s possibilities, I am happy with this purchase.
⭐ 5/5 | E***r: Super recommend, working normally, professional Automation, Instrumentalist, Electrical Engineer, recommend, arrived on time. Thank you, super recommend, arrived on time thank you.
⭐ 5/5 | a***r: Very precise when it comes to mA values. Easy to use.
⭐ 5/5 | S***z: The delivery was very fast, much earlier than the estimated date. So far I have been very satisfied, the equipment feels of very good quality and is very easy to use. It also came very well protected. 5 stars ⭐⭐⭐⭐⭐
⭐ 4/5 | AliExpress Shopper: Very good product. it is a pity that does not include the capability amongst varios types of signals also sine signals. For the rest it is excellent. if i have the opportunity to give an advise to the producer: attach a more comprehensive operational manual to get immediately the best out of this excellent instrument.
⭐ 5/5 | M***s: this is very good products.
⭐ 5/5 | A***q: Excellent equipment in accuracy and precision in measurement and Calibration.
⭐ 5/5 | D***o: Excellent value for money.
⭐ 5/5 | AliExpress Shopper: Very cool interface.
⭐ 3/5 | N***o: The device is not bad. I expected better accuracy, but it turned out as always.
⭐ 3/5 | D***r: The display is significantly rotated from its correct position.















