RI HP 1047A repair

[faris]

Hi there, it needs to be calibrated or may be repaired, there are no errors coming out of it and the light intensity is 5.1 (TP1/TP2) but we are getting top flat peaks and sometimes negative peas we are running lactic acid and the MP in water, if you know someone can calibrate or fix it please reply

[dap]

Hello.
Do you have negative peaks at the same solutions chromatograms? Negative peaks are usually OK for RI detector. Did you have no negative peaks some time ago?
Could you show some chromatograms please?