Tender For supply of hygrostat in duct design with internal adjust knob, measuring range 30-100% rh, measuring accuracy +/-4%, sensor length 220 mm, high grade steel, weight 0.7 kg, conforming to rdso specification no. rdso/pe/spec/ac/0061/2005 (rev-1), as per sidwal part no. sr-075-1022 & galltec make model no. hg80i, suitable for use in lhb ac coaches.