Specification :

HI 250 and HI 251 are precision pH meters that combine high tech with affordability. Both instruments can measure pH with centesimal resolution and perform automatic temperature compensation.
pH calibrations are customizable - up to 3 reference points, chosen from the 5 available memorized buffers - for a higher level of precision. Both have GLP features to display last calibration data at any time. They are also provided with an internal non-volatile memory storage that can save up to 50 data sets and downloaded to a PC via the RS232 connection.

HI 251 performs ORP measurements and displays pH measurements in the mV relative range. With relative mV ranging, the user can set any point to 0 mV and determine how much a reading differs from the starting point.

Both models are supplied complete with HI 1131B glass-body pH electrode and BNC connector for general purpose measurements and the HI 7669/ 2W temperature probe.

Specifications :
Range pH : -2.0 to 16.0 pH; 2.00 to 16.00 pH
Range mV : ± 699.9 mV; ± 2000 mV
Range Temperature : -9.9 to 120.0° C
Resolution pH : 0.1 pH; 0.01 pH
Resolution mV : 0.1 mV ( ± 699.9 mV) ;
1 mV ( ± 2000 mV)
Resolution Temperature : 0.1° C
Accuracy pH : ± 0.1 pH; ± 0.01 pH
Accuracy mV : ± 0.2 mV ( ± 699.9 mV) ;
± 1 mV ( ± 2000 mV)
Accuracy Temperature : ± 0.4° C
Relative mV Offset Range : ± 2000 mV
pH Calibration : automatic, 1, 2 or 3 point with 5 memorized values
( pH 4.01, 6.86, 7.01, 9.18, 10.01)
Temperature Compensation : Automatic ( with HI 7669/ 2W probe) or manual from -9.9 to 120° C
pH Electrode : HI 1131B, glass-body, double junction, refillable,
BNC connector, 1 m ( 3.3' ) cable ( included)
Temperature Probe : HI 7669/ 2W with 1 m ( 3.3' ) cable ( included)
Input Impedance : 1012 Ohm
PC Connection : RS232 opto-isolated serial port
Power Supply : 12 Vdc adapter ( included)
Environment : 0 to 50° C ( 32 to 122° F) ; RH max 95%
Dimensions : 40 x 182 x 74 mm ( 9.4 x 7.2 x 2.9" )
Weight : 1.1 kg ( 2.4 lb.)

Included Reagents :
- HI 70004
- HI 70007
- HI 7071S
- HI 7071