"Log On Demand" Function can record up to 500 settings with the HI 223 and 100 with the HI 221
Exclusive Cal-Check™ system prevents common calibration errors
Windows Compatible - With the HI 92000 software and an RS232 port, download the data to your PC to produce tables and graphic formats.

Specifications	HI 221	HI 223
pH Range	-2.00 to 16.00	-2.00 to 16.00 or -2.000 to 16.000
pH Accuracy	±0.01	±0.01; ±0.002
pH Resolution	0.01	0.01; 0.001
mV Range	-699.9 to 699.9; -2000 to 2000	-999.9 to 999.9; -2000 to 2000
mV Accuracy	±0.2; ±1	±0.2 (±699.9); ±0.5 (±999.9); ±1 (±2000)
mV Resolution	0.1, 1	0.1; 1
°C Range	-20.0 to 120.0	-20.0 to 120.0
°C Accuracy	±0.4	±0.4
°C Resolution	0.1	0.1
Temperature Comp.	Manual (MTC) or Automatic (ATC) temperature compensation
pH electrode	HI 1131P glass body, single junction refillable cell, BNC + pin (included)
Temperature probe	HI 7669/2W stainless steel probe (included)
PC Interface	Opto-isolated RS232
Logging	100 points	500 points
Input impedance	10¹² ohm
Power	12VDC adapter (included)
Environment	0 to 50°C (32 to 122°F) 95% RH
Dimensions	240 x 182 x 74mm (9.4 x 7.1 x 2.9")
Weight	1.1 Kg (2.5 lb.)