# Multimeter Unit UT139A CAT III with diode testing, handheld digital multimeter

**URL:** https://aio.lv/en/product--unit-ut139a--7703264
**Data updated:** 2026-04-26 18:24 (EEST)
**Category:** Measuring tools
**Manufacturer:** Unit
**Manufacturer code:** UT139A
**EAN:** 5901436796725
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 40.49 €
**Prices and availability valid until:** 2026-07-27 23:59
**Price without VAT (21%):** 33.46 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--unit-ut139a--7703264

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 07.07.2026 | free |
| Pickup points | 10.07.2026 | 1.89 EUR |
| Courier delivery to door | 10.07.2026 | 4.99 EUR |

## Summary description

Handheld digital multimeter Unit UT139A CAT III designed for measuring electrical parameters and performing diode tests. Provides basic measurement functions for voltage, current and resistance (model features vary), includes diode testing capability and CAT III safety rating for installation-level work. Suitable for electricians, technicians and DIY users for troubleshooting and routine electrical checks.

## Long description

Multimeter Unit UT139A CAT III with diode testing, handheld digital multimeter is a compact instrument designed for measuring common electrical parameters and performing diode checks. The Unit UT139A provides standard functions for voltage, current and resistance measurement, combined with a diode test mode and a CAT III safety rating suitable for installation-level tasks. Its handheld form factor makes it convenient for electricians, technicians and DIY users performing routine troubleshooting and verification on circuits and equipment.
Advantages
The Unit UT139A delivers a balance of essential measurement functions with a clear display and diode testing capability in a single handheld device. The CAT III safety rating allows measured circuits at installation level to be assessed with appropriate protection, while the meter's portable size supports field use and quick checks. Basic measurement coverage for voltage, current and resistance simplifies everyday diagnostics without the need for multiple instruments.
Suitable for
 Measuring AC and DC voltage on electrical installations and equipment
 Checking continuity and resistance in wiring and components
 Performing diode tests and simple semiconductor checks
 Troubleshooting household and light commercial electrical faults
 Routine maintenance and verification by electricians and technicians
When it may not be suitable
The Unit UT139A is intended for basic measurement tasks and may not be suitable where high-precision laboratory-grade readings are required. It is also not designed for specialty measurements such as low-frequency power analysis, high-current clamp measurements, or advanced waveform capture.
Key specifications
 Measurement functions: AC/DC voltage, current, resistance, diode test (feature set may vary by model)
 Safety rating: CAT III for installation-level use
 Form factor: handheld, portable design
 Display: digital readout for numerical measurements
 Typical applications: basic electrical troubleshooting and component checking
How to use
Start by selecting the appropriate measurement function and range if manual range selection is required, then connect the test leads to the meter and to the circuit points under test. For voltage and current measurements, observe proper polarity and safety practices, and ensure the meter is set to the correct AC or DC mode. Use the diode test function to verify semiconductor junctions by connecting the leads across the diode and reading the forward drop or open indication. Turn off power and discharge capacitors before performing resistance or continuity checks on circuits that are normally powered.
What to consider before purchase
 Confirm the required measurement ranges for voltage, current and resistance match your typical tasks
 Verify that CAT III safety rating is appropriate for the intended installation-level use
 Check whether additional features (e.g., true RMS, data hold, backlight) are needed for your work
 Consider the availability of replacement test leads and batteries for field operation
Usage recommendations
Always follow basic electrical safety procedures: inspect leads and meter for damage before use, do not exceed the specified measurement limits, and wear appropriate protective equipment when working on live installations. Use the diode test and resistance functions on de-energized circuits and select the correct measurement mode to obtain reliable readings.

## FAQ

### How much does the Multimeter Unit UT139A CAT III cost, and is it available for purchase?

The price is 40.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 57 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 07.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All Unit products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized Unit service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/7703264/51398476_large.webp