Winding resistance testers compared

Technical data of the 10 units of this type offered by Amperis, row by row. Tick «Compare» on two or three to see them side by side, copy the link or print the comparison.

Winding resistance testers compared

	RMO-TD Series: winding resistance meter	RMO-TT Series: winding resistance meter	RMO-TW Series: winding resistance meter	TWA Advanced Series: winding resistance	TWA Standard Series: winding resistance	TWR-H: turns ratio and winding resistance	TWR250B turns ratio and winding resistance analyzer	RMO-GM RMO-GM No product page on this site	RMO-M RMO-M No product page on this site	RMO-TH RMO-TH No product page on this site
Test current	5 mA – 60 A DC depending on model	5 mA – 100 A DC depending on model	5 mA – 50 A DC depending on model	5 mA – 25 A DC; up to 40 A DC during synchronisation check	5 mA – 25 A DC; up to 40 A DC in simultaneous YN mode (TWA40D)	Up to 2 A (HV side) and up to 10 A (LV side)	1 – 250 V AC; 5 mA – 25 A DC, up to 50 V	5 – 300 A DC; 300 A for 10 min, 200 A with unlimited test time	5 mA – 50 A DC (RMO50M); 5 mA – 100 A DC (RMO100M)	Source 1 (HV side): 5 mA – 2 A DC Source 2 (LV side): 0.5 – 10 A DC
Measuring range	0.1 µΩ – 100 kΩ	0.1 µΩ – 100 kΩ	0.1 µΩ – 100 kΩ	0.1 μΩ – 10 kΩ; from ±0.1% of reading	0.1 μΩ – 10 kΩ; from ±0.1% of reading	1 µΩ – 3 kΩ; ±(0.5% rdg + 0.5% FS)	0.1 µΩ – 100 kΩ	0.1 µΩ – 999.9 mΩ	0.1 µΩ – 1 kΩ	1 µΩ – 3 kΩ; resolution from 1 µΩ
Accuracy	±(0.1% rdg + 0.1% FS) up to 2 kΩ	±(0.1% rdg + 0.1% FS) up to 2 kΩ	±(0.1% rdg + 0.1% FS) up to 2 kΩ	Not stated on the product page	Not stated on the product page	Not stated on the product page	Not stated on the product page	±(0.1 % rdg + 0.1 % FS); resolution 0.1 µΩ	±(0.1 % rdg + 0.1 % FS)	±(0.5 % rdg + 0.5 % FS); ±(0.1 % rdg + 0.1 % FS) from 1 to 100 mΩ (RMO-THS)
Dynamic test (DVtest / OLTC)	0.1 ms sampling	DVtest (DRM): 0.1 ms sampling Vibration: ICP accelerometer, ±50 g Temperature: 4 Pt100 channels, -50 to +180 °C	4 ms sampling	0.1 ms, on one phase or all three at once	4 ms (TWA25A); 0.1 ms (TWA40D)	Not stated on the product page	DVtest and AC current channel: 1 ms resolution Temperature: -50 to +180 °C; Pt100 class B	Not stated in the documentation	Temperature: Pt100 class B, -50 to +180 °C	Not stated in the documentation
Models	RMO25TD, RMO40TD and RMO60TD	RMO40TT, RMO60TT and RMO100TT	RMO10TW, RMO20TW, RMO30TW and RMO50TW	TWA500 and TWA400	TWA25A and TWA40D	Not stated on the product page	Not stated on the product page	RMO300GM	RMO50M and RMO100M	RMO-TH; RMO-THS (high precision, on request)
Tests	Not stated on the product page	Not stated on the product page	Not stated on the product page	Three-phase, six windings, with a single cable connection	Three-phase, six windings, with a single cable connection	Ratio, winding resistance and demagnetization	Not stated on the product page	Winding resistance of generators and motors; 3 measuring channels and 1 temperature channel	Winding resistance of motors and generators; 3 simultaneous channels; automatic demagnetization	Winding resistance and demagnetization; single- and three-phase transformers, motors and generators
Output voltage	Up to 55 V DC	Not stated on the product page	Up to 55 V DC	Not stated on the product page	Not stated on the product page	Not stated on the product page	Not stated on the product page	8.2 V DC at 300 A; 8.6 V DC at 200 A (230 V AC mains)	Not stated in the documentation	Not stated in the documentation
Turns ratio	Not stated on the product page	Not stated on the product page	Not stated on the product page	Not stated on the product page	Not stated on the product page	0.8 – 20 000 (at 40/10 V AC); accuracy from ±0.1%	Turns ratio: 0.8 – 50,000; 5-digit resolution Phase angle and excitation current: 0 – 360° (0.01°); 0 – 2 A	Not stated in the documentation	Not stated in the documentation	Not stated in the documentation
Memory and communications	Not stated on the product page	Not stated on the product page	Not stated on the product page	10.1 in (TWA500) or 7 in (TWA400) touch screen; 32 GB	500 records; USB, with RS-232 optional	100 records; Bluetooth to PC	10.1" touch screen; 32 GB SD; Ethernet and USB	5000 records; USB, with optional RS-232 or Bluetooth	1000 records; USB, with optional RS-232 and thermal printer	4.8" LCD; 100 transformer records (15 results each); Bluetooth to PC
Power supply	Not stated on the product page	Not stated on the product page	90 – 264 V AC, 50/60 Hz; 2250 VA	Not stated on the product page	Not stated on the product page	14.8 V Li-Ion, replaceable; up to 100 tests	90 – 264 V AC, 50/60 Hz; 14.4 V, 6.8 Ah Li-ion battery	90 – 264 V AC, 50/60 Hz	90 – 264 V AC, 50/60 Hz; 600 VA (RMO50M) or 1200 VA (RMO100M)	Li-ion 14.8 V, 2.9 Ah, user-replaceable; adapter 90 – 264 V AC, 50/60 Hz
Safety and protection	IP67 with the lid closed	Not stated on the product page	Not stated on the product page	Not stated on the product page	Not stated on the product page	IP40; IP67 in the closed case	EN 61010-1:2010; EN 61326-1:2013; 3 years	Thermal and overcurrent protection; 20 A / 240 V circuit breaker; -20 to +55 °C	Thermal and overcurrent protection; -20 to +55 °C	EN 61010-1:2010; EN 61326-1:2013; IP40; IP67 in closed case
Dimensions and weight	478 × 194 × 389 mm; 13 – 13.2 kg	13.5 kg; 15.5 kg for the RMO100TT	198 × 250 × 350 mm; 8 – 8.5 kg	505 × 257 × 409 mm, 13.5 kg (TWA500); 543 × 218 × 427 mm, 15.0 kg (TWA400)	478 × 194 × 389 mm; 12.8 kg	170 × 310 × 58 mm; 1.4 kg	503 × 193 × 406 mm; 11.0 kg	503 × 406 × 193 mm; 14.6 kg	198 × 250 × 350 mm; 8 kg	170 × 310 × 58 mm; 1.4 kg
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