UNI-T UT18A Voltage i ispitivač kontinuiteta

Uvod

• The UNI-T UT18A is a professional-grade voltage and continuity tester designed for electricians, maintenance technicians, and other tradespeople. It provides quick LED-based (and in certain models: LCD) indication of AC/DC voltages, phase rotation in three-phase systems, polarity, and continuity, all within a compact pen-style form factor.
• Its design emphasizes safety (up to CAT IV 600 V) and versatility, making it suitable for industrial and commercial environments.

TEHNIČKI PODACI

• Voltage measurement range: up to approx 690 V AC/DC (for this series)
• Input protection: 600 Vrms (for some versions)
• Prekomjerni volumentage protection: ~750 VAC/DC for UT18A/B/C; other models go higher.
• Continuity test: 0 Ω…100 kΩ (approx) with buzzer & LED indicator
• Phase rotation test: 57 V-400 V (three-phase) for supported versions.
• Dimensions: 272 × 85 × 31 mm (approx)
• Battery: 2 × AAA (or IEC LR03) cells
• Safety category: CAT IV 600 V / CAT III 690 V (per series)
• Other features: LED indication, polarity detection, “no power” detection (voltage detection even without battery) on some models.

Korištenje

1. Voltage provjeriti: Connect the two test leads (or test pens) to the circuit or conductor you wish to test. The UT18A will light the corresponding LED(s) to indicate approximate voltage level. For AC/DC voltages up to ~690 V, it will indicate. (Always check actual manual for exact model limits.)
2. Polarity check: For DC circuits, the tester will indicate positive vs negative polarity (depending on model) when the probes are connected.
3. Test kontinuiteta: With the circuit de-energised, connect the leads across the component or conductor. A continuity LED and audible buzzer will indicate if resistance is within the continuity threshold (e.g., < 100 kΩ).
4. Phase rotation / three-phase test: In three-phase AC systems, the device can help indicate phase rotation or sequence by connecting between phases (depending on model support).
5. “No-power” detection: Some versions of the UT18 series allow basic voltage presence indication even if the internal battery is exhausted (voltage detection circuit still active) — helpful for checking live circuits when the tester battery is low.

Sigurnost

• Always assume a conductor is live until proven otherwise, and use the tester accordingly.
• Ensure you are using the tester within its rated category and voltage (e.g., CAT IV 600 V) environment. Using the rating above can lead to hazard.
• Wear appropriate personal protective equipment (PPE) when working on live circuits (gloves, eye protection, insulated tools).
• Before maintenance or continuity testing, make sure the circuit is de-energised and properly isolated.
• Connect the probes securely and avoid contact with exposed conductors. Do not hold the metal probe tips when measuring live circuits — hold only the insulated portion.
• The manual emphasises not using the instrument if it appears damaged, and maintenance/cleaning should be done while the tester is disconnected from any live circuit
• Check and replace batteries when low battery indication appears. A fatigued battery may cause unreliable readings.

Simboli navedeni u priručniku

• The manual includes necessary information regarding the safe usage and equipment maintenance and, before use, read through each section of the manual.
• Nepročitanje priručnika ili nerazumijevanje metode korištenja opreme navedene u priručniku dovelo bi do fizičkih ozljeda i oštećenja opreme.

Simbol na ploči testera i njegov opis (Slika 1)

1. Test pen L 1;
2. Test pen L2;
3. Voltage indikacija (LED);
4. LCD zaslon;
5. Visoki volumentage indikacija;
6. AC indication;
7. Indikacija kontinuiteta;
8. Polar indication;
9. Rotary phase indication:
10. RCD indication (LED);
11. RCD test button:
12. Flashlight/self-inspection button;
13. HOLD mode/backlight button;
14. Svjetiljka
15. Test pen cap;
16. Poklopac baterije

Slika 2 daje detaljan opis LCD panela.

1. Indikacija tihog načina rada;
2. Indikacija načina HOLD;
3. Niski volumentage indikator baterije;
4. Voltage mjerenje;
5. Mjerenje frekvencije;
6. DC voltage mjerenje
7. Izmjenični voltage mjerenje;
8. Voltage indication (LCD segment code);
9. Visoki volumentage indikacija;
10. Indikacija kontinuiteta;
11. RCD indikacija;
12. Indikacija rotacijske faze

Upute za rad i opseg uporabe testera

• Voltage and continuity tester includes four models: UT18A, UT 18B, IJT18C and UT18D, has such functions as ACIDC (including three-phase alternating current) voltage measurement, three-phase AC phase indication,  frequency measurement, RCD test, continuity test, the simple test in case of no battery power supply, self-inspection, silent mode choice, overvoltage indikacija i niskovoltage indikator baterije. Osim toga, svjetiljka pričvršćena na testnu olovku omogućuje praktičnu primjenu u tamnom okruženju.
• To protect tester and, more particularly, the tester user, the tester is equipped with protecting jacket. The tester should be put on protective jacket after use and, preferably, placed inside tool kit so as to protect it against any damage. Never place the tester into your pocket
• Tester je primjenjiv u raznim prilikama kao što su kućanstvo, tvornica, elektroenergetski odjel itd.

lt has the following characteristics:

1. Za zaštitu od fizičkih ozljeda, dizajniran je sa zaštitnom jaknom;
2. LED indication (UT18NB/C);
3. LCD voltage and frequency display (UT18C/D);
4. AC/DC mjereno do 690V;
5. Mjerenje kontinuiteta;
6. Navesti fazne odnose među trofaznim izmjeničnim strujama;
7. I zujanje i tihi način rada su opcijski;
8. Detection without battery (UTI 8A/B/C);
9. Illumination function;
10. Funkcija samokontrole;
11. Slaba baterija voltage indikacija i izmjereni voltage over range indication;
12. RCD test (UT18B/C/D);
13. Automatsko stanje pripravnosti.

Voltage mjerenje

• Pridržavajte se sigurnosnih propisa navedenih u točki 3.

Voltage gear of tester is composed of a line of LED or LCD segment codes, including 6V (UT18D), 12V, 24V, 50V, 120V.230V, 400V and 690V. LED (or LCD segment code) would be lighted one after another along with increased voltage, kao i indikator polariteta LED (ili kod segmenta LCD-a), indikator AC LED (ili kod segmenta LCD-a), indikator LED uključeno-isključeno (ili kod segmenta LCD-a), indikator RCD LED (ili kod segmenta LCD-a), indikator rotacijske faze LED (ili kod segmenta LCD-a) indikacija i visoka glasnoćatage LED (ili kod LCD segmenta) indikacija.

1. Complete self-check of tester before test. After pressing flashlight key 5s, tester would perform AC/DC  full range detection, accompanied by flashing LED (with exception to RCD light) and blinking displayed  LCD. If need to exit self-check, just touch the flashlight key. Connect two test pens to the conductor to be measured, select a known voltage for measurement, such as 220V socket, and ensure the measurement accuracy (See Figure 3), The tester cannot measure AC and DC voltage manji od 5V i ne daje točnu indikaciju dok se mjeri voltage je 5Vac/dc. Svjetlo za kontinuitet osvjetljenja ili AC svjetlo ili high-voltage symbol (IJT18D) and beeping buzzer are normal.
2. Tester would provide LED indication (UTI 8NB), LED+LCD indication (UT18C) and LCD indication (UT18D) while measuring AC or DC voltage. Visoka glasnoćatage LED će svijetliti i zvučni signal će se oglasiti kada se izmjeri voltage je ekstra niska voltage (ELV) prag. Ako se mjeri voltage nastavlja povećavati i premašiti ulaznu zaštitu voltage (750Vac/dc) of the tester, 12\E690V LED would keep flashing (IJTI 8A/B/C), LCD displays “OLP (UT18C/D) and buzzer keeps beeping.
3. Za mjerenje DC voltage, if 1-2 and Ll is connected respectively to the positive and negative pole of the object to be measured, LED would indicate the corresponding voltage, LCD prikazuje voltage, meanwhile the LED indicating positive pole would be illuminated, LCD displays “+9 “VDC” and, on the contrary, the LED indicating negative pole would be illuminated, LCD displays “-“”VDC”. If need to judge the positive and negative pole of the object to be measured, connect two test pens to the object to be measured randomly, the illuminating positive pole LED or LCD “+” on tester means the terminal connecting to L2 is the positive and the other connecting to Ll is the negative.
4. Za mjerenje AC voltage, two test pens may be randomly connected to two ends of the object to be measured, AC LED would be illuminated, LCD displays “VAC” while LED indicates the corresponding voltage vrijednost i LCD prikazuje odgovarajuću voltage vrijednost.
   Bilješka: Za mjerenje AC voltage, L and R phase inversion indication LED (UT18A/B/C) or L and R symbol (UT18D) would be illuminated, it means phase indication is unstable, L light (L symbol) or R light (R symbol) is illuminated, and even L and R light (L and R symbol) would be illuminated alternatively; L and R light (L and R symbol) would not provide correct and stable indication unless measuring three phase power system.

Detekcija bez baterije
Tester može izvršiti jednostavnu detekciju dok je baterija prazna ili dok baterija nije isporučena. Spojite dvije ispitne olovke na objekt koji se mjeri, kada predmet ima voltage više od ili ekvivalentno 50 V AC/120 V DC, visoki napontage LED će svijetliti, označavajući opasnu voltage i LED bi postupno svijetlio zajedno s povećanjem glasnoćetage to be measured. The function is applicable only to UTI 8A/B/C.

Test kontinuiteta
Za potvrdu je li vodič koji se mjeri naelektriziran, svtage measurement method may be adopted to measure voltage at both ends of the conductor by using two test pens. Connect two test pens to the both ends of the object to be measured, if the resistance falls within O 100kQ, continuity LED (UT18NB/C) or continuity symbol ” (UT18D) would be illuminated, accompanied by continuous beeping buzzer; and if resistance falls within 100kQ 150kQ, continuity LED (UTI 8A/B/C) or continuity symbol “ (UT18D) may or may not be illuminated and buzzer may or may not beep: if resistance is >150kQ, continuity LED (UTI 8NB/C) or continuity symbol ” ” (UT18D) may not be illuminated and buzzer would not beep. Before any test, be sure the object to be measured is not electrified.

Test rotacije (indikacija faze trofazne izmjenične struje)

• A The measurement must be conducted in accordance with the safety test regulations specified in item 3.
• Aln the case of strong electric field interference or strong radiation test phase sequence, the test results may be unstable.
• R, L LED ili simboli L i R primjenjivi su za ispitivanje rotacije, a ispitivanje je primjenjivo samo za trofazni AC sustav.

1. Trofazni voltage test range: 57V—400V (50Hz—60Hz);
2. Hold the main body of tester (with finger holding handle), as shown in the following figure, connect test pen L2 to any phase and Ll to any of remaining two phases,
3. R or L LED would be illuminated, and after connecting a test pen to another phase, another LED (L or R) would be illuminated,
4. L or R LED would be illuminated accordingly when the position of two test pens are exchanged,
5. LED bi pokazivao odgovarajuću voltage ili LCD prikazuje odgovarajuću voltage vrijednost, naznačena ili prikazana voltage treba biti faza voltage protiv zemlje ali trofazni voltage,

Dijagram ispitivanja trofaznog električnog sustava (Slika 4)

Bilješka: For measuring three-phase AC system, connect three measuring terminals to the corresponding terminal of three-phase system and, since the tester has only two test pen terminals, it is required to form the reference terminal by holding tester handle with finger (through the ground), therefore it would not accurately indicate the phase sequence of three-phase system if not holding the handle or wearing insulating gloves. In addition, it is necessary to ensure  the earth terminal (earth wire or shell) of three-phase system in contact with human body while measuring three-phase power system lower than 100V.

RCD test

• Za smanjenje smetnji voltage tijekom voltage measurement, a circuit with impedance lower than the tester under
  normal measurement mode may be provided between two test pens. namely the RCD circuit system.
• Za test okidanja RCD-a, spojite dvije ispitne olovke na L i PE terminal sustava od 230 Vac pod normalnom naponomtage measurement mode and press RCD key ” on two test pens, RCD system would trip and the LED indicating RCD (UT18B/C) or  RCD symbol (UT18D) would be illuminated if the circuit then generates AC current higher than 30mA. Particularly, if RCD cannot measure for a long time and, at 230V, the testing time should be <10s, cannot conduct continuous measurement and, after once test, wait 60s before next measurement.

Bilješka: U slučaju da nema mjerenja ili testiranja, normalno je imati neprekidno svijetleće LED i kontinuirani zvučni signal nakon istovremenog pritiskanja RCD tipki na dvije ispitne olovke. Kako biste izbjegli funkcionalni poremećaj, nemojte pritiskati dvije RCD tipke u načinu rada bez RCD testiranja.

Odabir tihog načina rada
It is allowed to enter the silent mode while tester is under standby mode or normally used. After pressing flashlight key about Is, tester would bleep and LCD displays silence symbol”” (UTI 8C/D), and tester enters silent mode and, under which mode, all functions are similar to those under normal mode, with exception to the silent buzzer. If need to resume normal mode (buzzing mode), press flashlight key about Is and, after “bleeps”, the silence symbol na LCD-u bi nestao.

Application of illumination function
Illumination function may be selected if need to use the tester at night or in a dark environment; after light touch on flashlight button on tester panel, the headlamp na vrhu testera će se uključiti kako bi vam olakšao rad i, nakon rada, ugasiti svjetlo laganim dodirom gumba.

Primjena pozadinskog osvjetljenja (primjenjivo samo za UT18D)
LCD displayed data may be hard to read at night or n a dark environment, allow the display clearly visible by turning on backlight on tester. Backlight would be turned on after pressing HOLD about Is and, after operation, turn off the light after pressing HOLD about Is. If tester enters standby mode while backlight is on, the light would remain illuminated when tester is awakened. The backlight cannot be turned off unless pressing HOLO about is again.

Application of HOLD function (UT18C/D)
Kako biste olakšali očitavanje i snimanje, držite izmjerene podatke (svtage and frequency value) by a light touch on HOLD on tester while using tester: after another Eght touch, hold status is relieved and restores to normal testing status,

Zamjena baterije
Prije uporabe voltage detector , Touch and hold the two probe tips together If shows and you hear the beeper, or in the silent mode ,  on . This makos sure that tho battery courco is not the battery source is exhausted.
Continuously flashing negative LED (IJTI ORB) or low-voltage symbol on LCD (IJTIdC/D) during use of tester indicates low-battery voltage i nužnost zamjene baterije.

Replate battery according to following procedures (as shown in Figure 5):

1. Stop measurement and disconnect Owo test pens from the object measured;
2. Odvijte vijke koji pričvršćuju poklopac baterije pomoću odvijača;
3. Uklonite poklopac baterije;
4. Izvadite bateriju koju želite zamijeniti;
5. Install new battery according to the battery symbol and direction indicated on panel: and
6. Umetnite poklopac baterije i pričvrstite ga vijcima.

Bilješka: Radi zaštite okoliša, baterije se mogu sakupljati i reciklirati na fiksnim sabirnim mjestima dok se jednokratna baterija ili akumulator odlaže u opasni otpad.

Slijedite lokalne važeće propise o recikliranju i odložite zamijenjene baterije u skladu s pravilima za odlaganje starih baterija i akumulatora.

Održavanje opreme
No special maintenance requirement is provided unless UTI 8A/B/C/D tester should be used as per manual instruction and, in case of any functional abnormality during normal operation, stop using immediately and contact the nearest authorized service center

Čišćenje opreme
Before cleaning, disconnect tester from the circuit being tested. If the instrument gets dirty during normal use. wipe it with wet cloth or small quantity of gentle household cleanser instead of acid cleanser or solvent. Do not use the tester within 5h after cleaning.

Tehnički indikator

Posebne funkcije

Indikator točnosti LCD zaslona:

Opis funkcija i parametara

• LED voltage range: 12V-690VAC/DC
• LED voltage indication point: 12V, 24V, 50V, 120M 230V, 400V, 690V
• LCD voltage range: 6v–690V AC/DC(UT18C/D); resolution: IV, voltage error: Digits);
• Frequency measurement range: 40Hz—400Hz, resolution: IHz, error: ±(3%+5Digits)
• Voltage measurement: Auto
• Buzzing and silent mode is optional.
• Oznaka polariteta: Automatski
• Range selection: Auto
• Response time: LED<O. 1 s/LCD<1 s
• Peak current of test circuit: ls<3.5mA (ac./dc)
• Vrijeme ispitivanja: 30s
• Vrijeme oporavka: 240s
• RCD test: Range: 230V (50Hz—400Hz); Current: AC30mA—40mA; Test time <10s, recovery time: 60s;
• Prekomjerni volumentage protection: 750VAC/DC
• On-off test: O kQ…100kQ; Accuracy: Rn+50%;
• Rotation test (three-phase AC): Voltage range: 57V—400V; Frequency range: 50 Hz—60Hz;
• A simple test (without battery): Voltage range: 50VAC&690VAC, 120VDC&690VDC (UT18A/B/C) ;
• Working temperature range: -15 C—+45 °C
• Storage temperature range: -20C—+60 °C
• Working humidity range: S85% RH
• Prekomjerni volumentage protection class: CAT III 690V, CAT IV 600V
• Klasa onečišćenja: 2
• safety rules IP65 EN61010-1 EN61243-3:2010
• Težina: 238g (uključujući bateriju);
• Dimensions: 272x85x 31mrn
• Battery IEC LR03 (AAA) x2

UNI-TREND TECHNOLOGY (KINA

• N06, Gong Ye Bei 1. cesta,
  Songshan Lake National High-Tech Industrial Development Zone, Dongguan City, Guangdong Province, Kina
• Tel: (86-769) 8572 3888
• http://www.uni-trend.com
• CO, LTD.

Sigurnosne mjere opreza
Kako biste spriječili tjelesne ozljede, električni udar ili požar, obratite posebnu pozornost na sljedeće stavke:

• Prije uporabe voltage detector with audible indicator at locations with a high background noise level, it has to be determined whether the audible signal is perceptible. the voltage detectors are designed to be used by skilled persons and in accordance with safe methods of work.
• Različiti indikacijski signali voltagDetektor (uključujući indikaciju granice GVE) ne smije se koristiti u svrhu mjerenja.
• Provjerite jesu li i testna olovka i testni instrument netaknuti prije testiranja;
• Pazite da vaša ruka bude u kontaktu samo s ručkom dok koristite opremu;
• Nikada nemojte koristiti opremu dok je voltage is beyond the range (referring to technical specification parameters)  and above 800V;
• Prije uporabe provjerite može li oprema dobro funkcionirati;
• Kako biste osigurali normalan rad ispitivača, izmjerite poznati volumentage vrijednost u prvom.
• Tester se više ne može koristiti u slučaju jednog ili više funkcionalnih kvarova ili bez funkcionalne indikacije.
• Nikada nemojte testirati u vlažnim uvjetima.
• Display functions well only when the temperature ranges -15C —+45 C and relative humidity is
• Instrument se mora popraviti u slučaju da se ne može jamčiti osobna sigurnost operatera.
• Sigurnost više ne bi bila zajamčena u bilo kojoj od sljedećih okolnosti:
  1. Visible damage;
  2. Tester’s functions are inconsistent with functions that it supposed to have.
  3. It had been stored in inappropriate conditions for a long time.
  4. Subject to mechanical extrusion in transit.

FAQ

Q1: Can the UT18A measure DC voltage as well as AC voltage?

A1: Yes. The UT18A supports both AC and DC voltage measurements (up to approximately 690 V in many models of the UT18 series). The manual lists AC/DC capability including polarity detection.

Q2: Does the UT18A allow me to test continuity without the internal battery?

A2: The UT18A (and certain models in the UT18 series) features a “no-power” detection mode: even if the internal battery is exhausted, the tester can still give a basic voltage presence indication when voltages exceed a certain threshold (e.g., > 50 V AC/120 V DC). However, for full continuity testing and full functionality you still need the battery.

Dokumenti / Resursi

UNI-T UT18A VoltagIspitivač e i kontinuiteta [pdf] Upute za uporabu UT18A svtage and Continunity Tester, UT18A, Voltage and Continunity Tester, Continunity Tester, Tester

Reference

• korisnički priručnik