Hanna Instruments HI 98180 Instruction Manual page 67

HI 1131B
Glass-body, single junction, refillable, combination pH electrode.
Use: general purpose.
HI 1330B
Glass-body, semimicro, single junction, refillable, combination pH electrode.
Use: laboratory, vials.
HI 1331B
Glass-body, semimicro, single junction, refillable, combination pH electrode.
Use: flasks.
HI 1230B
Plastic-body (PEI), double junction, gel-filled, combination pH electrode.
Use: general, field.
HI 2031B
Glass-body, semimicro, conic, refillable, combination pH electrode.
Use: semisolid products.
67